The Variation of Animals and Plants Under Domestication, Vol. I.
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Title: The Variation of Animals and Plants Under Domestication, Vol. I.
Author: Charles Darwin
Release date: March 27, 2008 [eBook #24923]
Language: English
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* * * * *
THE VARIATION
OF
ANIMALS AND PLANTS
UNDER DOMESTICATION.
BY CHARLES DARWIN, M.A., F.R.S., &c.
IN TWO VOLUMES.--VOL. I.
WITH ILLUSTRATIONS.
LONDON:
JOHN MURRAY, ALBEMARLE STREET.
1868.
_The right of Translation is reserved._
* * * * *
BY THE SAME AUTHOR.
* * * * *
ON THE ORIGIN OF SPECIES BY MEANS OF NATURAL SELECTION; or The PRESERVATION
of FAVOURED RACES in the STRUGGLE for LIFE. Fourth Edition (_Eighth
Thousand_), with Additions and Corrections. 1866. ... MURRAY.
A NATURALIST'S VOYAGE ROUND THE WORLD; or, A JOURNAL OF RESEARCHES into the
NATURAL HISTORY and GEOLOGY of the COUNTRIES visited during the Voyage of
H.M.S. Beagle, under the Command of Capt. FITZ-ROY, R.N. _Tenth Thousand_.
... MURRAY.
ON THE STRUCTURE AND DISTRIBUTION OF CORAL REEFS. ... SMITH, ELDER, & Co.
GEOLOGICAL OBSERVATIONS ON VOLCANIC ISLANDS. ... SMITH, ELDER, & Co.
GEOLOGICAL OBSERVATIONS ON SOUTH AMERICA. ... SMITH, ELDER, & Co.
A MONOGRAPH OF THE CIRRIPEDIA. With numerous Illustrations. 2 vols. 8vo.
... HARDWICKE.
ON THE VARIOUS CONTRIVANCES BY WHICH BRITISH AND FOREIGN ORCHIDS ARE
FERTILISED BY INSECTS; and on the GOOD EFFECTS of CROSSING. With numerous
Woodcuts. ... MURRAY.
ON THE MOVEMENTS and HABITS of CLIMBING PLANTS. With Woodcuts. ... WILLIAMS
& NORGATE.
* * * * *
LONDON: PRINTED BY WILLIAM CLOWES AND SONS, STAMFORD STREET, AND CHARING
CROSS.
* * * * *
{iii}
CONTENTS OF VOLUME I.
INTRODUCTION ... Page 1
CHAPTER I.
DOMESTIC DOGS AND CATS.
ANCIENT VARIETIES OF THE DOG--RESEMBLANCE OF DOMESTIC DOGS IN VARIOUS
COUNTRIES TO NATIVE CANINE SPECIES--ANIMALS NOT ACQUAINTED WITH MAN AT
FIRST FEARLESS--DOGS RESEMBLING WOLVES AND JACKALS--HABIT OF BARKING
ACQUIRED AND LOST--FERAL DOGS--TAN-COLOURED EYE-SPOTS--PERIOD OF
GESTATION--OFFENSIVE ODOUR--FERTILITY OF THE RACES WHEN
CROSSED--DIFFERENCES IN THE SEVERAL RACES IN PART DUE TO DESCENT FROM
DISTINCT SPECIES--DIFFERENCES IN THE SKULL AND TEETH--DIFFERENCES IN THE
BODY, IN CONSTITUTION--FEW IMPORTANT DIFFERENCES HAVE BEEN FIXED BY
SELECTION--DIRECT ACTION OF CLIMATE--WATER-DOGS WITH PALMATED FEET--HISTORY
OF THE CHANGES WHICH CERTAIN ENGLISH RACES OF THE DOG HAVE GRADUALLY
UNDERGONE THROUGH SELECTION--EXTINCTION OF THE LESS IMPROVED SUB-BREEDS.
CATS, CROSSED WITH SEVERAL SPECIES--DIFFERENT BREEDS FOUND ONLY IN
SEPARATED COUNTRIES--DIRECT EFFECTS OF THE CONDITIONS OF LIFE--FERAL
CATS--INDIVIDUAL VARIABILITY ... Page 15
CHAPTER II.
HORSES AND ASSES.
HORSE.--DIFFERENCES IN THE BREEDS--INDIVIDUAL VARIABILITY OF--DIRECT
EFFECTS OF THE CONDITIONS OF LIFE--CAN WITHSTAND MUCH COLD--BREEDS MUCH
MODIFIED BY SELECTION--COLOURS OF THE HORSE--DAPPLING--DARK STRIPES ON THE
SPINE, LEGS, SHOULDERS, AND FOREHEAD--DUN-COLOURED HORSES MOST FREQUENTLY
STRIPED--STRIPES PROBABLY DUE TO REVERSION TO THE PRIMITIVE STATE OF THE
HORSE.
ASSES.--BREEDS OF--COLOUR OF--LEG- AND SHOULDER-STRIPES--SHOULDER-STRIPES
SOMETIMES ABSENT, SOMETIMES FORKED ... Page 49
CHAPTER III.
PIGS--CATTLE--SHEEP--GOATS.
PIGS BELONG TO TWO DISTINCT TYPES, SUS SCROFA AND
INDICA--TORF-SCHWEIN--JAPAN PIG--FERTILITY OF CROSSED PIGS--CHANGES IN THE
SKULL OF THE HIGHLY CULTIVATED RACES--CONVERGENCE OF
CHARACTER--GESTATION--SOLID-HOOFED SWINE--CURIOUS APPENDAGES TO THE
JAWS--DECREASE IN SIZE OF THE TUSKS--YOUNG PIGS LONGITUDINALLY
STRIPED--FERAL PIGS--CROSSED BREEDS.
CATTLE.--ZEBU A DISTINCT SPECIES--EUROPEAN CATTLE PROBABLY DESCENDED FROM
THREE WILD FORMS--ALL THE RACES NOW FERTILE TOGETHER--BRITISH PARK
CATTLE--ON THE COLOUR OF THE ABORIGINAL SPECIES--CONSTITUTIONAL
DIFFERENCES--SOUTH AFRICAN RACES--SOUTH AMERICAN RACES--NIATA
CATTLE--ORIGIN OF THE VARIOUS RACES OF CATTLE. {iv}
SHEEP.--REMARKABLE RACES OF--VARIATIONS ATTACHED TO THE MALE
SEX--ADAPTATIONS TO VARIOUS CONDITIONS--GESTATION OF--CHANGES IN THE
WOOL--SEMI-MONSTROUS BREEDS.
GOATS.--REMARKABLE VARIATIONS OF ... Page 65
CHAPTER IV.
DOMESTIC RABBITS.
DOMESTIC RABBITS DESCENDED FROM THE COMMON WILD RABBIT--ANCIENT
DOMESTICATION--ANCIENT SELECTION--LARGE LOP-EARED RABBITS--VARIOUS
BREEDS--FLUCTUATING CHARACTERS--ORIGIN OF THE HIMALAYAN BREED--CURIOUS CASE
OF INHERITANCE--FERAL RABBITS IN JAMAICA AND THE FALKLAND ISLANDS--PORTO
SANTO FERAL RABBITS--OSTEOLOGICAL CHARACTERS--SKULL--SKULL OF HALF-LOP
RABBITS--VARIATIONS IN THE SKULL ANALOGOUS TO DIFFERENCES IN DIFFERENT
SPECIES OF HARES--VERTEBRAE--STERNUM--SCAPULA--EFFECTS OF USE AND DISUSE ON
THE PROPORTIONS OF THE LIMBS AND BODY--CAPACITY OF THE SKULL AND REDUCED
SIZE OF THE BRAIN--SUMMARY ON THE MODIFICATIONS OF DOMESTICATED RABBITS ...
Page 103
CHAPTER V.
DOMESTIC PIGEONS.
ENUMERATION AND DESCRIPTION OF THE SEVERAL BREEDS--INDIVIDUAL
VARIABILITY--VARIATIONS OF A REMARKABLE NATURE--OSTEOLOGICAL CHARACTERS:
SKULL, LOWER JAW, NUMBER OF VERTEBRAE--CORRELATION OF GROWTH: TONGUE WITH
BEAK; EYELIDS AND NOSTRILS WITH WATTLED SKIN--NUMBER OF WING-FEATHERS, AND
LENGTH OF WING--COLOUR AND DOWN--WEBBED AND FEATHERED FEET--ON THE EFFECTS
OF DISUSE--LENGTH OF FEET IN CORRELATION WITH LENGTH OF BEAK--LENGTH OF
STERNUM, SCAPULA, AND FURCULA--LENGTH OF WINGS--SUMMARY ON THE POINTS OF
DIFFERENCE IN THE SEVERAL BREEDS ... Page 131
CHAPTER VI.
PIGEONS--_continued_.
ON THE ABORIGINAL PARENT-STOCK OF THE SEVERAL DOMESTIC RACES--HABITS OF
LIFE--WILD RACES OF THE ROCK-PIGEON--DOVECOT-PIGEONS--PROOFS OF THE DESCENT
OF THE SEVERAL RACES FROM COLUMBA LIVIA--FERTILITY OF THE RACES WHEN
CROSSED--REVERSION TO THE PLUMAGE OF THE WILD ROCK-PIGEON--CIRCUMSTANCES
FAVOURABLE TO THE FORMATION OF THE RACES--ANTIQUITY AND HISTORY OF THE
PRINCIPAL RACES--MANNER OF THEIR FORMATION--SELECTION--UNCONSCIOUS
SELECTION--CARE TAKEN BY FANCIERS IN SELECTING THEIR BIRDS--SLIGHTLY
DIFFERENT STRAINS GRADUALLY CHANGE INTO WELL-MARKED BREEDS--EXTINCTION OF
INTERMEDIATE FORMS--CERTAIN BREEDS REMAIN PERMANENT, WHILST OTHERS
CHANGE--SUMMARY ... Page 180
{v}
CHAPTER VII.
FOWLS.
BRIEF DESCRIPTIONS OF THE CHIEF BREEDS--ARGUMENTS IN FAVOUR OF THEIR
DESCENT FROM SEVERAL SPECIES--ARGUMENTS IN FAVOUR OF ALL THE BREEDS HAVING
DESCENDED FROM GALLUS BANKIVA---REVERSION TO THE PARENT-STOCK IN
COLOUR--ANALOGOUS VARIATIONS--ANCIENT HISTORY OF THE FOWL--EXTERNAL
DIFFERENCES BETWEEN THE SEVERAL BREEDS--EGGS--CHICKENS--SECONDARY SEXUAL
CHARACTERS--WING- AND TAIL-FEATHERS, VOICE, DISPOSITION, ETC.--OSTEOLOGICAL
DIFFERENCES IN THE SKULL, VERTEBRAE, ETC.--EFFECTS OF USE AND DISUSE ON
CERTAIN PARTS--CORRELATION OF GROWTH ... Page 225
CHAPTER VIII.
DUCKS--GOOSE--PEACOCK--TURKEY--GUINEA-FOWL--CANARY-BIRD--GOLD-FISH--
HIVE-BEES--SILK-MOTHS.
DUCKS, SEVERAL BREEDS OF--PROGRESS OF DOMESTICATION--ORIGIN OF, FROM THE
COMMON WILD-DUCK--DIFFERENCES IN THE DIFFERENT BREEDS--OSTEOLOGICAL
DIFFERENCES--EFFECTS OF USE AND DISUSE ON THE LIMB-BONES.
GOOSE, ANCIENTLY DOMESTICATED--LITTLE VARIATION OF--SEBASTOPOL BREED.
PEACOCK, ORIGIN OF BLACK-SHOULDERED BREED.
TURKEY, BREEDS OF--CROSSED WITH THE UNITED STATES SPECIES--EFFECTS OF
CLIMATE ON.
GUINEA-FOWL, CANARY-BIRD, GOLD-FISH, HIVE-BEES.
SILK-MOTHS, SPECIES AND BREEDS OF--ANCIENTLY DOMESTICATED--CARE IN THEIR
SELECTION--DIFFERENCES IN THE DIFFERENT RACES--IN THE EGG, CATERPILLAR, AND
COCOON STATES--INHERITANCE OF CHARACTERS--IMPERFECT WINGS--LOST
INSTINCTS--CORRELATED CHARACTERS ... Page 276
CHAPTER IX.
CULTIVATED PLANTS: CEREAL AND CULINARY PLANTS.
PRELIMINARY REMARKS ON THE NUMBER AND PARENTAGE OF CULTIVATED PLANTS--FIRST
STEPS IN CULTIVATION--GEOGRAPHICAL DISTRIBUTION OF CULTIVATED PLANTS.
CEREALIA.--DOUBTS ON THE NUMBER OF SPECIES.--WHEAT: VARIETIES
OF--INDIVIDUAL VARIABILITY--CHANGED HABITS--SELECTION--ANCIENT HISTORY OF
THE VARIETIES.--MAIZE: GREAT VARIATION OF--DIRECT ACTION OF CLIMATE ON.
CULINARY PLANTS.--CABBAGES: VARIETIES OF, IN FOLIAGE AND STEMS, BUT NOT IN
OTHER PARTS--PARENTAGE OF--OTHER SPECIES OF BRASSICA.--PEAS: AMOUNT OF
DIFFERENCE IN THE SEVERAL KINDS, CHIEFLY IN THE PODS AND SEED--SOME
VARIETIES CONSTANT, SOME HIGHLY VARIABLE--DO NOT
INTERCROSS.--BEANS.--POTATOES: NUMEROUS VARIETIES OF--DIFFERING LITTLE,
EXCEPT IN THE TUBERS--CHARACTERS INHERITED ... Page 305
{vi}
CHAPTER X.
PLANTS _continued_--FRUITS--ORNAMENTAL TREES--FLOWERS.
FRUITS.--GRAPES--VARY IN ODD AND TRIFLING PARTICULARS.--MULBERRY.--THE
ORANGE GROUP--SINGULAR RESULTS FROM CROSSING.--PEACH AND
NECTARINE--BUD-VARIATION--ANALOGOUS VARIATION--RELATION TO THE
ALMOND.--APRICOT.--PLUMS--VARIATION IN THEIR STONES.--CHERRIES--SINGULAR
VARIETIES OF.--APPLE.--PEAR.--STRAWBERRY--INTERBLENDING OF THE ORIGINAL
FORMS.--GOOSEBERRY--STEADY INCREASE IN SIZE OF THE FRUIT--VARIETIES
OF.--WALNUT.--NUT.--CUCURBITACEOUS PLANTS--WONDERFUL VARIATION OF.
ORNAMENTAL TREES--THEIR VARIATION IN DEGREE AND
KIND--ASH-TREE--SCOTCH-FIR--HAWTHORN.
FLOWERS--MULTIPLE ORIGIN OF MANY KINDS--VARIATION IN CONSTITUTIONAL
PECULIARITIES--KIND OF VARIATION.--ROSES--SEVERAL SPECIES
CULTIVATED.--PANSY.--DAHLIA.--HYACINTH, HISTORY AND VARIATION OF ... Page
332
CHAPTER XI.
ON BUD-VARIATION, AND ON CERTAIN ANOMALOUS MODES OF REPRODUCTION AND
VARIATION.
BUD-VARIATIONS IN THE PEACH, PLUM, CHERRY, VINE, GOOSEBERRY, CURRANT, AND
BANANA, AS SHOWN BY THE MODIFIED FRUIT--IN FLOWERS: CAMELLIAS, AZALEAS,
CHRYSANTHEMUMS, ROSES, ETC.--ON THE RUNNING OF THE COLOUR IN
CARNATIONS--BUD-VARIATIONS IN LEAVES--VARIATIONS BY SUCKERS, TUBERS, AND
BULBS--ON THE BREAKING OF TULIPS--BUD-VARIATIONS GRADUATE INTO CHANGES
CONSEQUENT ON CHANGED CONDITIONS OF LIFE--CYTISUS ADAMI, ITS ORIGIN AND
TRANSFORMATION--ON THE UNION OF TWO DIFFERENT EMBRYOS IN ONE SEED--THE
TRIFACIAL ORANGE--ON REVERSION BY BUDS IN HYBRIDS AND MONGRELS--ON THE
PRODUCTION OF MODIFIED BUDS BY THE GRAFTING OF ONE VARIETY OR SPECIES ON
ANOTHER--ON THE DIRECT OR IMMEDIATE ACTION OF FOREIGN POLLEN ON THE
MOTHER-PLANT--ON THE EFFECTS IN FEMALE ANIMALS OF A FIRST IMPREGNATION ON
THE SUBSEQUENT OFFSPRING--CONCLUSION AND SUMMARY ... Page 373
* * * * *
{vii}
LIST OF ILLUSTRATIONS.
1. DUN DEVONSHIRE PONY, WITH SHOULDER, SPINAL, AND LEG STRIPES ... PAGE
56
2. HEAD OF JAPAN OR MASKED PIG ... 69
3. HEAD OF WILD BOAR, AND OF "GOLDEN DAYS," A PIG OF THE YORKSHIRE LARGE
BREED ... 72
4. OLD IRISH PIG, WITH JAW-APPENDAGES ... 75
5. HALF-LOP RABBIT ... 108
6. SKULL OF WILD RABBIT ... 117
7. SKULL OF LARGE LOP-EARED RABBIT ... 117
8. PART OF ZYGOMATIC ARCH, SHOWING THE PROJECTING END OF THE MALAR-BONE,
AND THE AUDITORY MEATUS, OF RABBITS ... 118
9. POSTERIOR END OF SKULL, SHOWING THE INTER-PARIETAL BONE, OF RABBITS
... 118
10. OCCIPITAL FORAMEN OF RABBITS ... 118
11. SKULL OF HALF-LOP RABBIT ... 119
12. ATLAS VERTEBRAE OF RABBITS ... 121
13. THIRD CERVICAL VERTEBRAE OF RABBITS ... 121
14. DORSAL VERTEBRAE, FROM SIXTH TO TENTH INCLUSIVE, OF RABBITS ... 122
15. TERMINAL BONE OF STERNUM OF RABBITS ... 123
16. ACROMION OF SCAPULA OF RABBITS ... 123
17. THE ROCK-PIGEON, OR COLUMBIA LIVIA ... 135
18. ENGLISH POUTER ... 137
19. ENGLISH CARRIER ... 140
20. ENGLISH BARB ... 145
21. ENGLISH FANTAIL ... 147
22. AFRICAN OWL ... 149
23. SHORT-FACED ENGLISH TUMBLER ... 152
24. SKULLS OF PIGEONS, VIEWED LATERALLY ... 163
25. LOWER JAWS OF PIGEONS, SEEN FROM ABOVE ... 164
26. SKULL OF RUNT, SEEN FROM ABOVE ... 165
27. LATERAL VIEW OF JAWS OF PIGEONS ... 165
28. SCAPULAE OF PIGEONS ... 167
29. FURCULAE OF PIGEONS ... 167
30. SPANISH FOWL ... 226
31. HAMBURGH FOWL ... 228
32. POLISH FOWL ... 229
33. OCCIPITAL FORAMEN OF THE SKULLS OF FOWLS ... 261
{viii}
34. SKULLS OF FOWLS, VIEWED FROM ABOVE, A LITTLE OBLIQUELY ... 262
35. LONGITUDINAL SECTIONS OF SKULLS OF FOWLS, VIEWED LATERALLY ... 263
36. SKULL OF HORNED FOWL, VIEWED FROM ABOVE, A LITTLE OBLIQUELY ... 265
37. SIXTH CERVICAL VERTEBRAE OF FOWLS, VIEWED LATERALLY ... 267
38. EXTREMITY OF THE FURCULA OF FOWLS, VIEWED LATERALLY ... 268
39. SKULLS OF DUCKS, VIEWED LATERALLY, REDUCED TO TWO-THIRDS OF THE
NATURAL SIZE ... 282
40. CERVICAL VERTEBRAE OF DUCKS, OF NATURAL SIZE ... 283
41. PODS OF THE COMMON PEA ... 328
42. PEACH AND ALMOND STONES, OF NATURAL SIZE, VIEWED EDGEWAYS ... 337
43. PLUM STONES, OF NATURAL SIZE, VIEWED LATERALLY ... 345
* * * * *
{1}
THE
VARIATION OF ANIMALS AND PLANTS
UNDER DOMESTICATION.
* * * * *
INTRODUCTION.
The object of this work is not to describe all the many races of animals
which have been domesticated by man, and of the plants which have been
cultivated by him; even if I possessed the requisite knowledge, so gigantic
an undertaking would be here superfluous. It is my intention to give under
the head of each species only such facts as I have been able to collect or
observe, showing the amount and nature of the changes which animals and
plants have undergone whilst under man's dominion, or which bear on the
general principles of variation. In one case alone, namely in that of the
domestic pigeon, I will describe fully all the chief races, their history,
the amount and nature of their differences, and the probable steps by which
they have been formed. I have selected this case, because, as we shall
hereafter see, the materials are better than in any other; and one case
fully described will in fact illustrate all others. But I shall also
describe domesticated rabbits, fowls, and ducks, with considerable
fullness.
The subjects discussed in this volume are so connected that it is not a
little difficult to decide how they can be best arranged. I have determined
in the first part to give, under the heads of the various animals and
plants, a large body of facts, some of which may at first appear but little
related to our subject, and to devote the latter part to general
discussions. Whenever I have found it necessary to give numerous details,
in support of any proposition or conclusion, small type has been used. The
reader {2} will, I think, find this plan a convenience, for, if he does not
doubt the conclusion or care about the details, he can easily pass them
over; yet I may be permitted to say that some of the discussions thus
printed deserve attention, at least from the professed naturalist.
It may be useful to those who have read nothing about Natural Selection, if
I here give a brief sketch of the whole subject and of its bearing on the
origin of species.[1] This is the more desirable, as it is impossible in
the present work to avoid many allusions to questions which will be fully
discussed in future volumes.
From a remote period, in all parts of the world, man has subjected many
animals and plants to domestication or culture. Man has no power of
altering the absolute conditions of life; he cannot change the climate of
any country; he adds no new element to the soil; but he can remove an
animal or plant from one climate or soil to another, and give it food on
which it did not subsist in its natural state. It is an error to speak of
man "tampering with nature" and causing variability. If organic beings had
not possessed an inherent tendency to vary, man could have done nothing.[2]
He unintentionally exposes his animals and plants to various conditions of
life, and variability supervenes, which he cannot even prevent or check.
Consider the simple case of a plant which has been cultivated during a long
time in its native country, and which consequently has not been subjected
to any change of climate. It has been protected to a certain extent from
the competing roots of plants of other kinds; it has generally been grown
in manured soil, but probably not richer than that of many an alluvial
flat; and lastly, it has been exposed to changes in its conditions, being
grown sometimes in one district and sometimes in another, in different
soils. Under such circumstances, {3} scarcely a plant can be named, though
cultivated in the rudest manner, which has not given birth to several
varieties. It can hardly be maintained that during the many changes which
this earth has undergone, and during the natural migrations of plants from
one land or island to another, tenanted by different species, that such
plants will not often have been subjected to changes in their conditions
analogous to those which almost inevitably cause cultivated plants to vary.
No doubt man selects varying individuals, sows their seeds, and again
selects their varying offspring. But the initial variation on which man
works, and without which he can do nothing, is caused by slight changes in
the conditions of life, which must often have occurred under nature. Man,
therefore, may be said to have been trying an experiment on a gigantic
scale; and it is an experiment which nature during the long lapse of time
has incessantly tried. Hence it follows that the principles of
domestication are important for us. The main result is that organic beings
thus treated have varied largely, and the variations have been inherited.
This has apparently been one chief cause of the belief long held by some
few naturalists that species in a state of nature undergo change.
I shall in this volume treat, as fully as my materials permit, the whole
subject of variation under domestication. We may thus hope to obtain some
light, little though it be, on the causes of variability,--on the laws
which govern it, such as the direct action of climate and food, the effects
of use and disuse, and of correlation of growth,--and on the amount of
change to which domesticated organisms are liable. We shall learn something
on the laws of inheritance, on the effects of crossing different breeds,
and on that sterility which often supervenes when organic beings are
removed from their natural conditions of life, and likewise when they are
too closely interbred. During this investigation we shall see that the
principle of Selection is all important. Although man does not cause
variability and cannot even prevent it, he can select, preserve, and
accumulate the variations given to him by the hand of nature in any way
which he chooses; and thus he can certainly produce a great result.
Selection may be followed either methodically and intentionally, or
unconsciously and unintentionally. Man {4} may select and preserve each
successive variation, with the distinct intention of improving and altering
a breed, in accordance with a preconceived idea; and by thus adding up
variations, often so slight as to be imperceptible by an uneducated eye, he
has effected wonderful changes and improvements. It can, also, be clearly
shown that man, without any intention or thought of improving the breed, by
preserving in each successive generation the individuals which he prizes
most, and by destroying the worthless individuals, slowly, though surely,
induces great changes. As the will of man thus comes into play, we can
understand how it is that domesticated breeds show adaptation to his wants
and pleasures. We can further understand how it is that domestic races of
animals and cultivated races of plants often exhibit an abnormal character,
as compared with natural species; for they have been modified not for their
own benefit, but for that of man.
In a second work I shall discuss the variability of organic beings in a
state of nature; namely, the individual differences presented by animals
and plants, and those slightly greater and generally inherited differences
which are ranked by naturalists as varieties or geographical races. We
shall see how difficult, or rather how impossible it often is, to
distinguish between races and sub-species, as the less well-marked forms
have sometimes been denominated; and again between sub-species and true
species. I shall further attempt to show that it is the common and widely
ranging, or, as they may be called, the dominant species, which most
frequently vary; and that it is the large and flourishing genera which
include the greatest number of varying species. Varieties, as we shall see,
may justly be called incipient species.
But it may be urged, granting that organic beings in a state of nature
present some varieties,--that their organization is in some slight degree
plastic; granting that many animals and plants have varied greatly under
domestication, and that man by his power of selection has gone on
accumulating such variations until he has made strongly marked and firmly
inherited races; granting all this, how, it may be asked, have species
arisen in a state of nature? The differences between natural varieties are
slight; whereas the differences are {5} considerable between the species of
the same genus, and great between the species of distinct genera. How do
these lesser differences become augmented into the greater difference? How
do varieties, or as I have called them incipient species, become converted
into true and well-defined species? How has each new species been adapted
to the surrounding physical conditions, and to the other forms of life on
which it in any way depends? We see on every side of us innumerable
adaptations and contrivances, which have justly excited in the mind of
every observer the highest admiration. There is, for instance, a fly
(Cecidomyia)[3] which deposits its eggs within the stamens of a
Scrophularia, and secretes a poison which produces a gall, on which the
larva feeds; but there is another insect (Misocampus) which deposits its
eggs within the body of the larva within the gall, and is thus nourished by
its living prey; so that here a hymenopterous insect depends on a dipterous
insect, and this depends on its power of producing a monstrous growth in a
particular organ of a particular plant. So it is, in a more or less plainly
marked manner, in thousands and tens of thousands of cases, with the lowest
as well as with the highest productions of nature.
This problem of the conversion of varieties into species,--that is, the
augmentation of the slight differences characteristic of varieties into the
greater differences characteristic of species and genera, including the
admirable adaptations of each being to its complex organic and inorganic
conditions of life,--will form the main subject of my second work. We shall
therein see that all organic beings, without exception, tend to increase at
so high a ratio, that no district, no station, not even the whole surface
of the land or the whole ocean, would hold the progeny of a single pair
after a certain number of generations. The inevitable result is an
ever-recurrent Struggle for Existence. It has truly been said that all
nature is at war; the strongest ultimately prevail, the weakest fail; and
we well know that myriads of forms have disappeared from the face of the
earth. If then organic beings in a state of nature vary even in a slight
degree, owing to changes in the surrounding {6} conditions, of which we
have abundant geological evidence, or from any other cause; if, in the long
course of ages, inheritable variations ever arise in any way advantageous
to any being under its excessively complex and changing relations of life;
and it would be a strange fact if beneficial variations did never arise,
seeing how many have arisen which man has taken advantage of for his own
profit or pleasure; if then these contingencies ever occur, and I do not
see how the probability of their occurrence can be doubted, then the severe
and often-recurrent struggle for existence will determine that those
variations, however slight, which are favourable shall be preserved or
selected, and those which are unfavourable shall be destroyed.
This preservation, during the battle for life, of varieties which possess
any advantage in structure, constitution, or instinct, I have called
Natural Selection; and Mr. Herbert Spencer has well expressed the same idea
by the Survival of the Fittest. The term "natural selection" is in some
respects a bad one, as it seems to imply conscious choice; but this will be
disregarded after a little familiarity. No one objects to chemists speaking
of "elective affinity;" and certainly an acid has no more choice in
combining with a base, than the conditions of life have in determining
whether or not a new form be selected or preserved. The term is so far a
good one as it brings into connection the production of domestic races by
man's power of selection, and the natural preservation of varieties and
species in a state of nature. For brevity sake I sometimes speak of natural
selection as an intelligent power;--in the same way as astronomers speak of
the attraction of gravity as ruling the movements of the planets, or as
agriculturists speak of man making domestic races by his power of
selection. In the one case, as in the other, selection does nothing without
variability, and this depends in some manner on the action of the
surrounding circumstances on the organism. I have, also, often personified
the word Nature; for I have found it difficult to avoid this ambiguity; but
I mean by nature only the aggregate action and product of many natural
laws,--and by laws only the ascertained sequence of events. {7}
In the chapter devoted to natural selection I shall show from experiment
and from a multitude of facts, that the greatest amount of life can be
supported on each spot by great diversification or divergence in the
structure and constitution of its inhabitants. We shall, also, see that the
continued production of new forms through natural selection, which implies
that each new variety has some advantage over others, almost inevitably
leads to the extermination of the older and less improved forms. These
latter are almost necessarily intermediate in structure as well as in
descent between the last-produced forms and their original parent-species.
Now, if we suppose a species to produce two or more varieties, and these in
the course of time to produce other varieties, the principle of good being
derived from diversification of structure will generally lead to the
preservation of the most divergent varieties; thus the lesser differences
characteristic of varieties come to be augmented into the greater
differences characteristic of species, and, by the extermination of the
older intermediate forms, new species come to be distinctly defined
objects. Thus, also, we shall see how it is that organic beings can be
classed by what is called a natural method in distinct groups--species
under genera, and genera under families.
As all the inhabitants of each country may be said, owing to their high
rate of reproduction, to be striving to increase in numbers; as each form
is related to many other forms in the struggle for life,--for destroy any
one and its place will be seized by others; as every part of the
organization occasionally varies in some slight degree, and as natural
selection acts exclusively by the preservation of variations which are
advantageous under the excessively complex conditions to which each being
is exposed, no limit exists to the number, singularity, and perfection of
the contrivances and co-adaptations which may thus be produced. An animal
or a plant may thus slowly become related in its structure and habits in
the most intricate manner to many other animals and plants, and to the
physical conditions of its home. Variations in the organization will in
some cases be aided by habit, or by the use and disuse of parts, and they
will be governed by the direct action {8} of the surrounding physical
conditions and by correlation of growth.
On the principles here briefly sketched out, there is no innate or
necessary tendency in each being to its own advancement in the scale of
organization. We are almost compelled to look at the specialization or
differentiation of parts or organs for different functions as the best or
even sole standard of advancement; for by such division of labour each
function of body and mind is better performed. And, as natural selection
acts exclusively through the preservation of profitable modifications of
structure, and as the conditions of life in each area generally become more
and more complex, from the increasing number of different forms which
inhabit it and from most of these forms acquiring a more and more perfect
structure, we may confidently believe, that, on the whole, organization
advances. Nevertheless a very simple form fitted for very simple conditions
of life might remain for indefinite ages unaltered or unimproved; for what
would it profit an infusorial animalcule, for instance, or an intestinal
worm, to become highly organized? Members of a high group might even
become, and this apparently has occurred, fitted for simpler conditions of
life; and in this case natural selection would tend to simplify or degrade
the organization, for complicated mechanism for simple actions would be
useless or even disadvantageous.
In a second work, after treating of the Variation of organisms in a state
of nature, of the Struggle for Existence and the principle of Natural
Selection, I shall discuss the difficulties which are opposed to the
theory. These difficulties may be classed under the following heads:--the
apparent impossibility in some cases of a very simple organ graduating by
small steps into a highly perfect organ; the marvellous facts of Instinct;
the whole question of Hybridity; and, lastly, the absence, at the present
time and in our geological formations, of innumerable links connecting all
allied species. Although some of these difficulties are of great weight, we
shall see that many of them are explicable on the theory of natural
selection, and are otherwise inexplicable.
In scientific investigations it is permitted to invent any hypothesis, and
if it explains various large and independent classes of facts it rises to
the rank of a well-grounded theory. The {9} undulations of the ether and
even its existence are hypothetical, yet every one now admits the
undulatory theory of light. The principle of natural selection may be
looked at as a mere hypothesis, but rendered in some degree probable by
what we positively know of the variability of organic beings in a state of
nature,--by what we positively know of the struggle for existence, and the
consequent almost inevitable preservation of favourable variations,--and
from the analogical formation of domestic races. Now this hypothesis may be
tested,--and this seems to me the only fair and legitimate manner of
considering the whole question,--by trying whether it explains several
large and independent classes of facts; such as the geological succession
of organic beings, their distribution in past and present times, and their
mutual affinities and homologies. If the principle of natural selection
does explain these and other large bodies of facts, it ought to be
received. On the ordinary view of each species having been independently
created, we gain no scientific explanation of any one of these facts. We
can only say that it has so pleased the Creator to command that the past
and present inhabitants of the world should appear in a certain order and
in certain areas; that He has impressed on them the most extraordinary
resemblances, and has classed them in groups subordinate to groups. But by
such statements we gain no new knowledge; we do not connect together facts
and laws; we explain nothing.
In a third work I shall try the principle of natural selection by seeing
how far it will give a fair explanation of the several classes of facts
just alluded to. It was the consideration of these facts which first led me
to take up the present subject. When I visited, during the voyage of H.M.S.
_Beagle_, the Galapagos Archipelago, situated in the Pacific Ocean about
500 miles from the shore of South America, I found myself surrounded by
peculiar species of birds, reptiles, and plants, existing nowhere else in
the world. Yet they nearly all bore an American stamp. In the song of the
mocking-thrush, in the harsh cry of the carrion-hawk, in the great
candlestick-like opuntias, I clearly perceived the neighbourhood of
America, though the islands were separated by so many miles of ocean from
the mainland, and differed much from it in their geological {10}
constitution and climate. Still more surprising was the fact that most of
the inhabitants of each separate island in this small archipelago were
specifically different, though most closely related to each other. The
archipelago, with its innumerable craters and bare streams of lava,
appeared to be of recent origin; and thus I fancied myself brought near to
the very act of creation. I often asked myself how these many peculiar
animals and plants had been produced: the simplest answer seemed to be that
the inhabitants of the several islands had descended from each other,
undergoing modification in the course of their descent; and that all the
inhabitants of the archipelago had descended from those of the nearest
land, namely America, whence colonists would naturally have been derived.
But it long remained to me an inexplicable problem how the necessary degree
of modification could have been effected, and it would have thus remained
for ever, had I not studied domestic productions, and thus acquired a just
idea of the power of Selection. As soon as I had fully realized this idea,
I saw, on reading Malthus on Population, that Natural Selection was the
inevitable result of the rapid increase of all organic beings; for I was
prepared to appreciate the struggle for existence by having long studied
the habits of animals.
Before visiting the Galapagos I had collected many animals whilst
travelling from north to south on both sides of America, and everywhere,
under conditions of life as different as it is possible to conceive,
American forms were met with--species replacing species of the same
peculiar genera. Thus it was when the Cordilleras were ascended, or the
thick tropical forests penetrated, or the fresh waters of America searched.
Subsequently I visited other countries, which in all the conditions of life
were incomparably more like to parts of South America, than the different
parts of that continent were to each other; yet in these countries, as in
Australia or Southern Africa, the traveller cannot fail to be struck with
the entire difference of their productions. Again the reflection was forced
on me that community of descent from the early inhabitants or colonists of
South America would alone explain the wide prevalence of American types of
structure throughout that immense area.
To exhume with one's own hands the bones of extinct and {11} gigantic
quadrupeds brings the whole question of the succession of species vividly
before one's mind; and I had found in South America great pieces of
tesselated armour exactly like, but on a magnificent scale, that covering
the pigmy armadillo; I had found great teeth like those of the living
sloth, and bones like those of the cavy. An analogous succession of allied
forms had been previously observed in Australia. Here then we see the
prevalence, as if by descent, in time as in space, of the same types in the
same areas; and in neither case does the similarity of the conditions by
any means seem sufficient to account for the similarity of the forms of
life. It is notorious that the fossil remains of closely consecutive
formations are closely allied in structure, and we can at once understand
the fact if they are likewise closely allied by descent. The succession of
the many distinct species of the same genus throughout the long series of
geological formations seems to have been unbroken or continuous. New
species come in gradually one by one. Ancient and extinct forms of life
often show combined or intermediate characters, like the words of a dead
language with respect to its several offshoots or living tongues. All these
and other such facts seemed to me to point to descent with modification as
the method of production of new groups of species.
The innumerable past and present inhabitants of the world are connected
together by the most singular and complex affinities, and can be classed in
groups under groups, in the same manner as varieties can be classed under
species and sub-varieties under varieties, but with much higher grades of
difference. It will be seen in my third work that these complex affinities
and the rules for classification receive a rational explanation on the
principle of descent, together with modifications acquired through natural
selection, entailing divergence of character and the extinction of
intermediate forms. How inexplicable is the similar pattern of the hand of
a man, the foot of a dog, the wing of a bat, the flipper of a seal, on the
doctrine of independent acts of creation! how simply explained on the
principle of the natural selection of successive slight variations in the
diverging descendants from {12} a single progenitor! So it is, if we look
to the structure of an individual animal or plant, when we see the fore and
hind limbs, the skull and vertebrae, the jaws and legs of a crab, the
petals, stamens, and pistils of a flower, built on the same type or
pattern. During the many changes to which in the course of time all organic
beings have been subjected, certain organs or parts have occasionally
become at first of little use and ultimately superfluous; and the retention
of such parts in a rudimentary and utterly useless condition can, on the
descent-theory, be simply understood. On the principle of modifications
being inherited at the same age in the child, at which each successive
variation first appeared in the parent, we shall see why rudimentary parts
and organs are generally well developed in the individual at a very early
age. On the same principle of inheritance at corresponding ages, and on the
principle of variations not generally supervening at a very early period of
embryonic growth (and both these principles can be shown to be probable
from direct evidence), that most wonderful fact in the whole round of
natural history, namely, the similarity of members of the same great class
in their embryonic condition,--the embryo, for instance, of a mammal, bird,
reptile, and fish being barely distinguishable,--becomes simply
intelligible.
It is the consideration and explanation of such facts as these which has
convinced me that the theory of descent with modification by means of
natural selection is in the main true. These facts have as yet received no
explanation on the theory of independent Creations; they cannot be grouped
together under one point of view, but each has to be considered as an
ultimate fact. As the first origin of life on this earth, as well as the
continued life of each individual, is at present quite beyond the scope of
science, I do not wish to lay much stress on the greater simplicity of the
view of a few forms, or of only one form, having been originally created,
instead of innumerable miraculous creations having been necessary at
innumerable periods; though this more simple view accords well with
Maupertuis's philosophical axiom "of least action."
In considering how far the theory of natural selection may be {13}
extended,--that is, in determining from how many progenitors the
inhabitants of the world have descended,--we may conclude that at least all
the members of the same class have descended from a single ancestor. A
number of organic beings are included in the same class, because they
present, independently of their habits of life, the same fundamental type
of structure, and because they graduate into each other. Moreover, members
of the same class can in most cases be shown to be closely alike at an
early embryonic age. These facts can be explained on the belief of their
descent from a common form; therefore it may be safely admitted that all
the members of the same class have descended from one progenitor. But as
the members of quite distinct classes have something in common in structure
and much in common in constitution, analogy and the simplicity of the view
would lead us one step further, and to infer as probable that all living
creatures have descended from a single prototype.
I hope that the reader will pause before coming to any final and hostile
conclusion on the theory of natural selection. It is the facts and views to
be hereafter given which have convinced me of the truth of the theory. The
reader may consult my 'Origin of Species,' for a general sketch of the
whole subject; but in that work he has to take many statements on trust. In
considering the theory of natural selection, he will assuredly meet with
weighty difficulties, but these difficulties relate chiefly to
subjects--such as the degree of perfection of the geological record, the
means of distribution, the possibility of transitions in organs, &c.--on
which we are confessedly ignorant; nor do we know how ignorant we are. If
we are much more ignorant than is generally supposed, most of these
difficulties wholly disappear. Let the reader reflect on the difficulty of
looking at whole classes of facts from a new point of view. Let him observe
how slowly, but surely, the noble views of Lyell on the gradual changes now
in progress on the earth's surface have been accepted as sufficient to
account for all that we see in its past history. The present action of
natural selection may seem more or less probable; but I believe in the
truth of the theory, {14} because it collects under one point of view, and
gives a rational explanation of, many apparently independent classes of
facts.[4]
* * * * *
{15}
CHAPTER I.
DOMESTIC DOGS AND CATS.
ANCIENT VARIETIES OF THE DOG--RESEMBLANCE OF DOMESTIC DOGS IN VARIOUS
COUNTRIES TO NATIVE CANINE SPECIES--ANIMALS NOT ACQUAINTED WITH MAN AT
FIRST FEARLESS--DOGS RESEMBLING WOLVES AND JACKALS--HABIT OF BARKING
ACQUIRED AND LOST--FERAL DOGS--TAN-COLOURED EYE-SPOTS PERIOD OF
GESTATION--OFFENSIVE ODOUR--FERTILITY OF THE RACES WHEN
CROSSED--DIFFERENCES IN THE SEVERAL RACES IN PART DUE TO DESCENT FROM
DISTINCT SPECIES--DIFFERENCES IN THE SKULL AND TEETH--DIFFERENCES IN
THE BODY, IN CONSTITUTION--FEW IMPORTANT DIFFERENCES HAVE BEEN FIXED BY
SELECTION--DIRECT ACTION OF CLIMATE--WATER-DOGS WITH PALMATED
FEET--HISTORY OF THE CHANGES WHICH CERTAIN ENGLISH RACES OF THE DOG
HAVE GRADUALLY UNDERGONE THROUGH SELECTION--EXTINCTION OF THE LESS
IMPROVED SUB-BREEDS.
CATS, CROSSED WITH SEVERAL SPECIES--DIFFERENT BREEDS FOUND ONLY IN
SEPARATED COUNTRIES--DIRECT EFFECTS OF THE CONDITIONS OF LIFE--FERAL
CATS--INDIVIDUAL VARIABILITY.
The first and chief point of interest in this chapter is, whether the
numerous domesticated varieties of the dog have descended from a single
wild species, or from several. Some authors believe that all have descended
from the wolf, or from the jackal, or from an unknown and extinct species.
Others again believe, and this of late has been the favourite tenet, that
they have descended from several species, extinct and recent, more or less
commingled together. We shall probably never be able to ascertain their
origin with certainty. Palaeontology[5] does not throw much light on the
question, owing, on the one hand, to the close similarity of the skulls of
extinct as well as living wolves and jackals, and owing on the other hand
to the great dissimilarity of the skulls of the several breeds of the
domestic dogs. It seems, however, that remains have been found in the {16}
later tertiary deposits more like those of a large dog than of a wolf,
which favours the belief of De Blainville that our dogs are the descendants
of a single extinct species. On the other hand, some authors go so far as
to assert that every chief domestic breed must have had its wild prototype.
This latter view is extremely improbable; it allows nothing for variation;
it passes over the almost monstrous character of some of the breeds; and it
almost necessarily assumes, that a large number of species have become
extinct since man domesticated the dog; whereas we plainly see that the
members of the dog-family are extirpated by human agency with much
difficulty; even so recently as 1710 the wolf existed in so small an island
as Ireland.
The reasons which have led various authors to infer that our dogs have
descended from more than one wild species are as follows.[6] Firstly, the
great difference between the several breeds; but this will appear of
comparatively little weight, after we shall have seen how great are the
differences between the several races of various domesticated animals which
certainly have descended from a single parent-form. Secondly, the more
important fact that, at the most anciently known historical periods,
several breeds of the dog existed, very unlike each other, and closely
resembling or identical with breeds still alive.
We will briefly run back through the historical records. The materials are
remarkably deficient between the fourteenth century and the Roman classical
period.[7] At this earlier period {17} various breeds, namely hounds,
house-dogs, lapdogs, &c., existed; but as Dr. Walther has remarked it is
impossible to recognise the greater number with any certainty. Youatt,
however, gives a drawing of a beautiful sculpture of two greyhound puppies
from the Villa of Antoninus. On an Assyrian monument, about 640 B.C., an
enormous mastiff[8] is figured; and according to Sir H. Rawlinson (as I was
informed at the British Museum), similar dogs are still imported into this
same country. I have looked through the magnificent works of Lepsius and
Rosellini, and on the monuments from the fourth to the twelfth dynasties
(_i.e._ from about 3400 B.C. to 2100 B.C.) several varieties of the dog are
represented; most of them are allied to greyhounds; at the later of these
periods a dog resembling a hound is figured, with drooping ears, but with a
longer back and more pointed head than in our hounds. There is, also, a
turnspit, with short and crooked legs, closely resembling the existing
variety; but this kind of monstrosity is so common with various animals, as
with the ancon sheep, and even, according to Rengger, with jaguars in
Paraguay, that it would be rash to look at the monumental animal as the
parent of all our turnspits: Colonel Sykes[9] also has described an Indian
Pariah dog as presenting the same monstrous character. The most ancient dog
represented on the Egyptian monuments is one of the most singular; it
resembles a greyhound, but has long pointed ears and a short curled tail: a
closely allied variety still exists in Northern Africa; for Mr. E. Vernon
Harcourt[10] states that the Arab boar-hound is "an eccentric hieroglyphic
animal, such as Cheops once hunted with, somewhat resembling the rough
Scotch deer-hound; their tails are curled tight round on their backs, {18}
and their ears stick out at right angles." With this most ancient variety a
pariah-like dog coexisted.
We thus see that, at a period between four and five thousand years ago,
various breeds, viz. pariah dogs, greyhounds, common hounds, mastiffs,
house-dogs, lapdogs, and turnspits, existed, more or less closely
resembling our present breeds. But there is not sufficient evidence that
any of these ancient dogs belonged to the same identical sub-varieties with
our present dogs.[11] As long as man was believed to have existed on this
earth only about 6000 years, this fact of the great diversity of the breeds
at so early a period was an argument of much weight that they had proceeded
from several wild sources, for there would not have been sufficient time
for their divergence and modification. But now that we know, from the
discovery of flint tools embedded with the remains of extinct animals in
districts which have since undergone great geographical changes, that man
has existed for an incomparably longer period, and bearing in mind that the
most barbarous nations possess domestic dogs, the argument from
insufficient time falls away greatly in value.
Long before the period of any historical record the dog was domesticated in
Europe. In the Danish Middens of the Neolithic or Newer Stone period, bones
of a canine animal are imbedded, and Steenstrup ingeniously argues that
these belonged to a domestic dog; for a very large proportion of the bones
of birds preserved in the refuse, consists of long bones, which it was
found on trial dogs cannot devour.[12] This ancient dog was succeeded in
Denmark during the Bronze period by a larger kind, presenting certain
differences, and this again during the Iron period, by a still larger kind.
In Switzerland, we hear {19} from Prof. Ruetimeyer,[13] that during the
Neolithic period a domesticated dog of middle size existed, which in its
skull was about equally remote from the wolf and jackal, and partook of the
characters of our hounds and setters or spaniels (Jagdhund und
Wachtelhund). Ruetimeyer insists strongly on the constancy of form during a
very long period of time of this the most ancient known dog. During the
Bronze period a larger dog appeared, and this closely resembled in its jaw
a dog of the same age in Denmark. Remains of two notably distinct varieties
of the dog were found by Schmerling in a cave;[14] but their age cannot be
positively determined.
The existence of a single race, remarkably constant in form during the
whole Neolithic period, is an interesting fact in contrast with what we see
of the changes which the races underwent during the period of the
successive Egyptian monuments, and in contrast with our existing dogs. The
character of this animal during the Neolithic period, as given by
Ruetimeyer, supports De Blainville's view that our varieties have descended
from an unknown and extinct form. But we should not forget that we know
nothing with respect to the antiquity of man in the warmer parts of the
world. The succession of the different kinds of dogs in Switzerland and
Denmark is thought to be due to the immigration of conquering tribes
bringing with them their dogs; and this view accords with the belief that
different wild canine animals were domesticated in different regions.
Independently of the immigration of new races of man, we know from the
wide-spread presence of bronze, composed of an alloy of tin, how much
commerce there must have been throughout Europe at an extremely remote
period, and dogs would then probably have been bartered. At the present
time, amongst the savages of the interior of Guiana, the Taruma Indians are
considered the best trainers of dogs, and possess a large breed, which they
barter at a high price with other tribes.[15]
The main argument in favour of the several breeds of the {20} dog being the
descendants of distinct wild stocks, is their resemblance in various
countries to distinct species still existing there. It must, however, be
admitted that the comparison between the wild and domesticated animal has
been made but in few cases with sufficient exactness. Before entering on
details, it will be well to show that there is no a priori difficulty in
the belief that several canine species have been domesticated; for there is
much difficulty in this respect with some other domestic quadrupeds and
birds. Members of the dog family inhabit nearly the whole world; and
several species agree pretty closely in habits and structure with our
several domesticated dogs. Mr. Galton has shown[16] how fond savages are of
keeping and taming animals of all kinds. Social animals are the most easily
subjugated by man, and several species of Canidae hunt in packs. It deserves
notice, as bearing on other animals as well as on the dog, that at an
extremely ancient period, when man first entered any country, the animals
living there would have felt no instinctive or inherited fear of him, and
would consequently have been tamed far more easily than at present. For
instance, when the Falkland Islands were first visited by man, the large
wolf-like dog (_Canis antarcticus_) fearlessly came to meet Byron's
sailors, who, mistaking this ignorant curiosity for ferocity, ran into the
water to avoid them: even recently a man, by holding a piece of meat in one
hand and a knife in the other, could sometimes stick them at night. On an
island in the Sea of Aral, when first discovered by Butakoff, the saigak
antelopes, which are "generally very timid and watchful, did not fly from
us, but on the contrary looked at us with a sort of curiosity." So, again,
on the shores of the Mauritius, the manatee was not at first in the least
afraid of man, and thus it has been in several quarters of the world with
seals and the morse. I have elsewhere shown[17] how slowly the native birds
of several islands have acquired and inherited a salutary dread of man: at
the Galapagos Archipelago I pushed with the muzzle of my gun hawks from a
branch, and {21} held out a pitcher of water for other birds to alight on
and drink. Quadrupeds and birds which have seldom been disturbed by man,
dread him no more than do our English birds the cows or horses grazing in
the fields.
It is a more important consideration that several canine species evince (as
will be shown in a future chapter) no strong repugnance or inability to
breed under confinement; and the incapacity to breed under confinement is
one of the commonest bars to domestication. Lastly, savages set the highest
value, as we shall see in the chapter on Selection, on dogs: even
half-tamed animals are highly useful to them: the Indians of North America
cross their half-wild dogs with wolves, and thus render them even wilder
than before, but bolder: the savages of Guiana catch and partially tame and
use the whelps of two wild species of _Canis_, as do the savages of
Australia those of the wild Dingo. Mr. Philip King informs me that he once
trained a wild Dingo puppy to drive cattle, and found it very useful. From
these several considerations we see that there is no difficulty in
believing that man might have domesticated various canine species in
different countries. It would indeed have been a strange fact if one
species alone had been domesticated throughout the world.
We will now enter into details. The accurate and sagacious Richardson says,
"The resemblance between the Northern American wolves (_Canis lupus, var.
occidentalis_) and the domestic dogs of the Indians is so great that the
size and strength of the wolf seems to be the only difference. I have more
than once mistaken a band of wolves for the dogs of a party of Indians; and
the howl of the animals of both species is prolonged so exactly in the same
key that even the practised ear of the Indian fails at times to
discriminate them." He adds that the more northern Esquimaux dogs are not
only extremely like the grey wolves of the Arctic circle in form and
colour, but also nearly equal them in size. Dr. Kane has often seen in his
teams of sledge-dogs the oblique eye (a character on which some naturalists
lay great stress), the drooping tail, and scared look of the wolf. In
disposition the Esquimaux dogs differ little from wolves, and, according to
Dr. Hayes, they are capable of no attachment to man, and are so savage,
that {22} when hungry they will attack even their masters. According to
Kane they readily become feral. Their affinity is so close with wolves that
they frequently cross with them, and the Indians take the whelps of wolves
"to improve the breed of their dogs." The half-bred wolves sometimes
(Lamare-Picquot) cannot be tamed, "though this case is rare;" but they do
not become thoroughly well broken in till the second or third generation.
These facts show that there can be but little, if any, sterility between
the Esquimaux dog and the wolf, for otherwise they would not be used to
improve the breed. As Dr. Hayes says of these dogs, "reclaimed wolves they
doubtless are."[18]
North America is inhabited by a second kind of wolf, the prairie-wolf
(_Canis latrans_), which is now looked at by all naturalists as
specifically distinct from the common wolf; and is, according to Mr. J. K.
Lord, in some respects intermediate in habits between a wolf and a fox. Sir
J. Richardson, after describing the Hare Indian dog, which differs in many
respects from the Esquimaux dog, says, "It bears the same relation to the
prairie wolf that the Esquimaux dog does to the great grey wolf." He could,
in fact, detect no marked difference between them; and Messrs. Nott and
Gliddon give additional details showing their close resemblance. The dogs
derived from the above two aboriginal sources cross together and with the
wild wolves, at least with the _C. occidentalis_, and with European dogs.
In Florida, according to Bartram, the black wolf-dog of the Indians differs
in nothing from the wolves of that country except in barking.[19]
{23}
Turning to the southern parts of the New World, Columbus found two kinds of
dogs in the West Indies; and Fernandez[20] describes three in Mexico: some
of these native dogs were dumb--that is, did not bark. In Guiana it has
been known since the time of Buffon that the natives cross their dogs with
an aboriginal species, apparently the _Canis cancrivorus_. Sir R.
Schomburgk, who has so carefully explored these regions, writes to me, "I
have been repeatedly told by the Arawaak Indians, who reside near the
coast, that they cross their dogs with a wild species to improve the breed,
and individual dogs have been shown to me which certainly resembled the _C.
cancrivorus_ much more than the common breed. It is but seldom that the
Indians keep the _C. cancrivorus_ for domestic purposes, nor is the Ai,
another species of wild dog, and which I consider to be identical with the
_Dusicyon silvestris_ of H. Smith, now much used by the Arecunas for the
purpose of hunting. The dogs of the Taruma Indians are quite distinct, and
resemble Buffon's St. Domingo greyhound." It thus appears that the natives
of Guiana have partially domesticated two aboriginal species, and still
cross their dogs with them; these two species belong to a quite different
type from the North American and European wolves. A careful observer,
Rengger,[21] gives reasons for believing that a hairless dog was
domesticated when America was first visited by Europeans: some of these
dogs in Paraguay are still dumb, and Tschudi[22] states that they suffer
from cold in the Cordillera. This naked dog is, however, quite distinct
from that found preserved in the ancient Peruvian burial-places, and
described by Tschudi, under the name of _Canis Ingae_, as withstanding cold
well and as barking. It is not known whether these two distinct kinds of
dog are the descendants of native species, and it might be argued that when
man first migrated into America he brought with him from the Asiatic
continent dogs {24} which had not learned to bark; but this view does not
seem probable, as the natives along the line of their march from the north
reclaimed, as we have seen, at least two N. American species of Canidae.
Turning to the Old World, some European dogs closely resemble the wolf;
thus the shepherd dog of the plains of Hungary is white or reddish-brown,
has a sharp nose, short, erect ears, shaggy coat, and bushy tail, and so
much resembles a wolf that Mr. Paget, who gives this description, says he
has known a Hungarian mistake a wolf for one of his own dogs. Jeitteles,
also, remarks on the close similarity of the Hungarian dog and wolf.
Shepherd dogs in Italy must anciently have closely resembled wolves, for
Columella (vii. 12) advises that white dogs be kept, adding, "pastor album
probat, ne pro lupo canem feriat." Several accounts have been given of dogs
and wolves crossing naturally; and Pliny asserts that the Gauls tied their
female dogs in the woods that they might cross with wolves.[23] The
European wolf differs slightly from that of North America, and has been
ranked by many naturalists as a distinct species. The common wolf of India
is also by some esteemed as a third species, and here again we find a
marked resemblance between the pariah dogs of certain districts of India
and the Indian wolf.[24]
With respect to Jackals, Isidore Geoffroy Saint Hilaire[25] says that not
one constant difference can be pointed out between their structure and that
of the smaller races of dogs. They agree closely in habits: jackals, when
tamed and called by their {25} master, wag their tails, crouch, and throw
themselves on their backs; they smell at the tails of dogs, and void their
urine sideways.[26] A number of excellent naturalists, from the time of
Gueldenstaedt to that of Ehrenberg, Hemprich, and Cretzschmar, have expressed
themselves in the strongest terms with respect to the resemblance of the
half-domestic dogs of Asia and Egypt to jackals. M. Nordmann, for instance,
says, "Les chiens d'Awhasie ressemblent etonnamment a des chacals."
Ehrenberg[27] asserts that the domestic dogs of Lower Egypt, and certain
mummied dogs, have for their wild type a species of wolf (_C. lupaster_) of
the country; whereas the domestic dogs of Nubia and certain other mummied
dogs have the closest relation to a wild species of the same country, viz.
_C. sabbar_, which is only a form of the common jackal. Pallas asserts that
jackals and dogs sometimes naturally cross in the East; and a case is on
record in Algeria.[28] The greater number of naturalists divide the jackals
of Asia and Africa into several species, but some few rank them all as one.
I may add that the domestic dogs on the coast of Guinea are fox-like
animals, and are dumb.[29] On the east coast of Africa, between lat. 4 deg. and
6 deg. south, and about ten days' journey in the interior, a semi-domestic dog,
as the Rev. S. Erhardt informs me, is kept, which the natives assert is
derived from a similar wild animal. Lichtenstein[30] says that the dogs of
the Bosjemans present a striking resemblance even in colour (excepting the
black stripe down the back) with the _C. mesomelas_ of South Africa. Mr. E.
Layard informs me that he has seen a Caffre dog which closely resembled an
Esquimaux dog. In Australia the Dingo is both domesticated and wild; though
this animal may have been introduced aboriginally by man, yet it must be
considered as almost an endemic form, for its remains have been found in a
similar state of preservation and associated with {26} extinct mammals, so
that its introduction must have been ancient.[31]
From this resemblance in several countries of the half-domesticated dogs to
the wild species still living there,--from the facility with which they can
often be crossed together,--from even half-tamed animals being so much
valued by savages,--and from the other circumstances previously remarked on
which favour their domestication, it is highly probable that the domestic
dogs of the world have descended from two good species of wolf (viz. _C.
lupus_ and _C. latrans_), and from two or three other doubtful species of
wolves (namely, the European, Indian, and North African forms); from at
least one or two South American canine species; from several races or
species of the jackal; and perhaps from one or more extinct species. Those
authors who attribute great influence to the action of climate by itself
may thus account for the resemblance of the domesticated dogs and native
animals in the same countries; but I know of no facts supporting the belief
in so powerful an action of climate.
It cannot be objected to the view of several canine species having been
anciently domesticated, that these animals are tamed with difficulty: facts
have been already given on this head, but I may add that the young of the
_Canis primaevus_ of India were tamed by Mr. Hodgson,[32] and became as
sensible to caresses, and manifested as much intelligence, as any sporting
dog of the same age. There is not much difference, as we have already shown
and shall immediately further see, in habits between the domestic dogs of
the North American Indians and the wolves of that country, or between the
Eastern pariah dogs and jackals, or between the dogs which have run wild in
various countries and the several natural species of the family. The habit
of barking, however, which is almost universal with domesticated {27} dogs,
and which does not characterise a single natural species of the family,
seems an exception; but this habit is soon lost and soon reacquired. The
case of the wild dogs on the island of Juan Fernandez having become dumb
has often been quoted, and there is reason to believe[33] that the dumbness
ensued in the course of thirty-three years; on the other hand, dogs taken
from this island by Ulloa slowly reacquired the habit of barking. The
Mackenzie-river dogs, of the _Canis latrans_ type, when brought to England,
never learned to bark properly; but one born in the Zoological Gardens[34]
"made his voice sound as loudly as any other dog of the same age and size."
According to Professor Nillson,[35] a wolf-whelp reared by a bitch barks.
I. Geoffroy Saint Hilaire exhibited a jackal which barked with the same
tone as any common dog.[36] An interesting account has been given by Mr. G.
Clarke[37] of some dogs run wild on Juan de Nova, in the Indian Ocean;
"they had entirely lost the faculty of barking; they had no inclination for
the company of other dogs, nor did they acquire their voice," during a
captivity of several months. On the island they "congregate in vast packs,
and catch sea-birds with as much address as foxes could display." The feral
dogs of La Plata have not become dumb; they are of large size, hunt single
or in packs, and burrow holes for their young.[38] In these habits the
feral dogs of La Plata resemble wolves and jackals; both of which hunt
either singly or in packs, and burrow holes.[39] These feral dogs have not
become uniform in colour on Juan Fernandez, Juan de Nova, or La Plata.[40]
In Cuba the feral dogs are described by Poeppig as nearly all
mouse-coloured, with short ears and light-blue eyes. {28} In St. Domingo,
Col. Ham. Smith says[41] that the feral dogs are very large, like
greyhounds, of a uniform pale blue-ash, with small ears, and large
light-brown eyes. Even the wild Dingo, though so anciently naturalised in
Australia, "varies considerably in colour," as I am informed by Mr. P. P.
King: a half-bred Dingo reared in England[42] showed signs of wishing to
burrow.
From the several foregoing facts we see that reversion in the feral
state gives no indication of the colour or size of the aboriginal
parent-species. One fact, however, with respect to the colouring of
domestic dogs, I at one time hoped might have thrown some light on
their origin; and it is worth giving, as showing how colouring follows
laws, even in so anciently and thoroughly domesticated an animal as the
dog. Black dogs with tan-coloured feet, whatever breed they may belong
to, almost invariably have a tan-coloured spot on the upper and inner
corners of each eye, and their lips are generally thus coloured. I have
seen only two exceptions to this rule, namely, in a spaniel and
terrier. Dogs of a light-brown colour often have a lighter,
yellowish-brown spot over the eyes; sometimes the spot is white, and in
a mongrel terrier the spot was black. Mr. Waring kindly examined for me
a stud of fifteen greyhounds in Suffolk: eleven of them were black, or
black and white, or brindled, and these had no eye-spots; but three
were red and one slaty-blue, and these four had dark-coloured spots
over their eyes. Although the spots thus sometimes differ in colour,
they strongly tend to be tan-coloured; this is proved by my having seen
four spaniels, a setter, two Yorkshire shepherd dogs, a large mongrel,
and some fox-hounds, coloured black and white, with not a trace of
tan-colour, excepting the spots over the eyes, and sometimes a little
on the feet. These latter cases, and many others, show plainly that the
colour of the feet and the eye-spots are in some way correlated. I have
noticed, in various breeds, every gradation, from the whole face being
tan-coloured, to a complete ring round the eyes, to a minute spot over
the inner and upper corners. The spots occur in various sub-breeds of
terriers and spaniels; in setters; in hounds of various kinds,
including the turnspit-like German badger-hound; in shepherd dogs; in a
mongrel, of which neither parent had the spots; in one pure bulldog,
though the spots were in this case almost white; and in
greyhounds,--but true black-and-tan greyhounds are excessively rare;
nevertheless I have been assured by Mr. Warwick, that one ran at the
Caledonian Champion meeting of April, 1860, and was "marked precisely
like a black-and-tan terrier." Mr. Swinhoe at my request looked at the
dogs in China, at Amoy, and he soon noticed a brown dog with yellow
spots over the eyes. Colonel H. Smith[43] figures the magnificent black
mastiff of Thibet with a {29} tan-coloured stripe over the eyes, feet,
and chaps; and what is more singular, he figures the Alco, or native
domestic dog of Mexico, as black and white, with narrow tan-coloured
rings round the eyes; at the Exhibition of dogs in London, May, 1863, a
so-called forest-dog from North-West Mexico was shown, which had pale
tan-coloured spots over the eyes. The occurrence of these tan-coloured
spots in dogs of such extremely different breeds, living in various
parts of the world, makes the fact highly remarkable.
We shall hereafter see, especially in the chapter on Pigeons, that
coloured marks are strongly inherited, and that they often aid us in
discovering the primitive forms of our domestic races. Hence, if any
wild canine species had distinctly exhibited the tan-coloured spots
over the eyes, it might have been argued that this was the parent-form
of nearly all our domestic races. But after looking at many coloured
plates, and through the whole collection of skins in the British
Museum, I can find no species thus marked. It is no doubt possible that
some extinct species was thus coloured. On the other hand, in looking
at the various species, there seems to be a tolerably plain correlation
between tan-coloured legs and face; and less frequently between black
legs and a black face; and this general rule of colouring explains to a
certain extent the above-given cases of correlation between the
eye-spots and the colour of the feet. Moreover, some jackals and foxes
have a trace of a white ring round their eyes, as in _C. mesomelas_,
_C. aureus_, and (judging from Colonel Ham. Smith's drawing) in _C.
alopex_ and _C. thaleb_. Other species have a trace of a black line
over the corners of the eyes, as in _C. variegatus_,
_cinereo-variegatus_, and _fulvus_, and the wild Dingo. Hence I am
inclined to conclude that a tendency for tan-coloured spots to appear
over the eyes in the various breeds of dogs, is analogous to the case
observed by Desmarest, namely, that when any white appears on a dog the
tip of the tail is always white, "de maniere a rappeler la tacho
terminale de meme couleur, qui caracterise la plupart des Canidees
sauvages."[44]
It has been objected that our domestic dogs cannot be descended from wolves
or jackals, because their periods of gestation are different. The supposed
difference rests on statements made by Buffon, Gilibert, Bechstein, and
others; but these are now known to be erroneous; and the period is found to
agree in the wolf, jackal, and dog, as closely as could be expected, for it
is often in some degree variable.[45] Tessier, who {30} has closely
attended to this subject, allows a difference of four days in the gestation
of the dog. The Rev. W. D. Fox has given me three carefully recorded cases
of retrievers, in which the bitch was put only once to the dog; and not
counting this day, but counting that of parturition, the periods were
fifty-nine, sixty-two, and sixty-seven days. The average period is
sixty-three days; but Bellingeri states that this holds good only with
large dogs; and that for small races it is from sixty to sixty-three days;
Mr. Eyton of Eyton, who has had much experience with dogs, also informs me
that the time is apt to be longer with large than with small dogs.
F. Cuvier has objected that the jackal would not have been domesticated on
account of its offensive smell; but savages are not sensitive in this
respect. The degree of odour, also, differs in the different kinds of
jackal;[46] and Colonel H. Smith makes a sectional division of the group
with one character dependent on not being offensive. On the other hand,
dogs--for instance, rough and smooth terriers--differ much in this respect;
and M. Godron states that the hairless so-called Turkish dog is more
odoriferous than other dogs. Isidore Geoffroy[47] gave to a dog the same
odour as that from a jackal by feeding it on raw flesh.
The belief that our dogs are descended from wolves, jackals, South American
Canidae, and other species, suggests a far more important difficulty. These
animals in their undomesticated state, judging from a widely-spread
analogy, would have been in some degree sterile if intercrossed; and such
sterility will be admitted as almost certain by all those who believe that
the lessened fertility of crossed forms is an infallible criterion of
specific distinctness. Anyhow these animals keep distinct in the countries
which they inhabit in common. On the other hand, all domestic dogs, which
are here supposed to be descended {31} from several distinct species, are,
as far as is known, mutually fertile together. But, as Broca has well
remarked,[48] the fertility of successive generations of mongrel dogs has
never been scrutinised with that care which is thought indispensable when
species are crossed. The few facts leading to the conclusion that the
sexual feelings and reproductive powers differ in the several races of the
dog when crossed are (passing over mere size as rendering propagation
difficult) as follows: the Mexican Alco[49] apparently dislikes dogs of
other kinds, but this perhaps is not strictly a sexual feeling; the
hairless endemic dog of Paraguay, according to Rengger, mixes less with the
European races than these do with each other; the Spitz-dog in Germany is
said to receive the fox more readily than do other breeds; and Dr. Hodgkin
states that a female Dingo in England attracted the male wild foxes. If
these latter statements can be trusted, they prove some degree of sexual
difference in the breeds of the dog. But the fact remains that our domestic
dogs, differing so widely as they do in external structure, are far more
fertile together than we have reason to believe their supposed wild parents
would have been. Pallas assumes[50] that a long course of domestication
eliminates that sterility which the parent-species would have exhibited if
only lately captured; no distinct facts are recorded in support of this
hypothesis; but the evidence seems to me so strong (independently of the
evidence derived from other domesticated animals) in favour of our domestic
dogs having descended from several wild stocks, that I am led to admit the
truth of this hypothesis.
There is another and closely allied difficulty consequent on the doctrine
of the descent of our domestic dogs from several wild species, namely, that
they do not seem to be perfectly fertile with their supposed parents. But
the experiment has not been quite fairly tried; the Hungarian dog, for
instance, {32} which in external appearance so closely resembles the
European wolf, ought to be crossed with this wolf; and the pariah-dogs of
India with Indian wolves and jackals; and so in other cases. That the
sterility is very slight between certain dogs and wolves and other Canidae
is shown by savages taking the trouble to cross them. Buffon got four
successive generations from the wolf and dog, and the mongrels were
perfectly fertile together.[51] But more lately M. Flourens states
positively as the result of his numerous experiments that hybrids from the
wolf and dog, crossed _inter se_, become sterile at the third generation,
and those from the jackal and dog at the fourth generation.[52] But these
animals were closely confined; and many wild animals, as we shall see in a
future chapter, are rendered by confinement in some degree or even utterly
sterile. The Dingo, which breeds freely in Australia with our imported
dogs, would not breed though repeatedly crossed in the Jardin des
Plantes.[53] Some hounds from Central Africa, brought home by Major Denham,
never bred in the Tower of London;[54] and a similar tendency to sterility
might be transmitted to the hybrid offspring of a wild animal. Moreover, it
appears that in M. Flourens' experiments the hybrids were closely bred in
and in for three or four generations; but this circumstance, although it
would almost certainly increase the tendency to sterility, would hardly
account for the final result, even though aided by close confinement,
unless there had been some original tendency to lessened fertility. Several
years ago I saw confined in the Zoological Gardens of London a female
hybrid from an English dog and jackal, which even in this the first
generation was so sterile that, as I was assured by {33} her keeper, she
did not fully exhibit her proper periods; but this case, from the numerous
instances of fertile hybrids from these two animals, was certainly
exceptional. In almost all experiments on the crossing of animals there are
so many causes of doubt, that it is extremely difficult to come to any
positive conclusion. It would, however, appear, that those who believe that
our dogs are descended from several species will have not only to admit
that their offspring after a long course of domestication generally lose
all tendency to sterility when crossed together; but that between certain
breeds of dogs and some of their supposed aboriginal parents a certain
degree of sterility has been retained or possibly even acquired.
Notwithstanding the difficulties in regard to fertility given in the last
two paragraphs, when we reflect on the inherent improbability of man having
domesticated throughout the world one single species alone of so widely
distributed, so easily tamed, and so useful a group as the Canidae; when we
reflect on the extreme antiquity of the different breeds; and especially
when we reflect on the close similarity, both in external structure and
habits, between the domestic dogs of various countries and the wild species
still inhabiting these same countries, the balance of evidence is strongly
in favour of the multiple origin of our dogs.
* * * * *
_Differences between the several Breeds of the Dog._--If the several breeds
have descended from several wild stocks, their difference can obviously in
part be explained by that of their parent-species. For instance, the form
of the greyhound may be partly accounted for by descent from some such
animal as the slim Abyssinian _Canis simensis_,[55] with its elongated
muzzle; that of the larger dogs from the larger wolves, and the smaller and
slighter dogs from jackals: and thus perhaps we may account for certain
constitutional and climatal differences. But it would be a great error to
suppose that there has not been in addition[56] a large amount of
variation. The intercrossing of the several aboriginal wild stocks, and of
the subsequently formed {34} races, has probably increased the total number
of breeds, and, as we shall presently see, has greatly modified some of
them. But we cannot explain by crossing the origin of such extreme forms as
thoroughbred greyhounds, bloodhounds, bulldogs, Blenheim spaniels,
terriers, pugs, &c., unless we believe that forms equally or more strongly
characterised in these different respects once existed in nature. But
hardly any one has been bold enough to suppose that such unnatural forms
ever did or could exist in a wild state. When compared with all known
members of the family of Canidae they betray a distinct and abnormal origin.
No instance is on record of such dogs as bloodhounds, spaniels, true
greyhounds having been kept by savages: they are the product of
long-continued civilization.
The number of breeds and sub-breeds of the dog is great: Youatt, for
instance, describes twelve kinds of greyhounds. I will not attempt to
enumerate or describe the varieties, for we cannot discriminate how
much of their difference is due to variation, and how much to descent
from different aboriginal stocks. But it may be worth while briefly to
mention some points. Commencing with the skull, Cuvier has admitted[57]
that in form the differences are "plus fortes que celles d'aucunes
especes sauvages d'un meme genre naturel." The proportions of the
different bones; the curvature of the lower jaw, the position of the
condyles with respect to the plane of the teeth (on which F. Cuvier
founded his classification), and in mastiffs the shape of its posterior
branch; the shape of the zygomatic arch, and of the temporal fossae; the
position of the occiput--all vary considerably.[58] The dog has
properly six pairs of molar teeth in the upper jaw, and seven in the
lower; but several naturalists have seen not rarely an additional pair
in the upper jaw;[59] and Professor Gervais says that there are dogs
"qui ont sept paires de dents superieures et huit inferieures.". De
Blainville[60] has given full particulars on the frequency of these
deviations in the number of the teeth, and has shown that it is not
always the same tooth which is supernumerary. In short-muzzled races,
according to H. Mueller,[61] the molar teeth stand obliquely, whilst in
long-muzzled races they are placed longitudinally, with open spaces
between them. The naked, so-called Egyptian or Turkish dog is extremely
deficient in its {35} teeth,[62]--sometimes having none except one
molar on each side; but this, though characteristic of the breed, must
be considered as a monstrosity. M. Girard,[63] who seems to have
attended closely to the subject, says that the period of the appearance
of the permanent teeth differs in different dogs, being earlier in
large dogs; thus the mastiff assumes its adult teeth in four or five
months, whilst in the spaniel the period is sometimes more than seven
or eight months.
With respect to minor differences little need be said. Isidore Geoffroy
has shown[64] that in size some dogs are six times as long (the tail
being excluded) as others; and that the height relatively to the length
of the body varies from between one to two, and one to nearly four. In
the Scotch deer-hound there is a striking and remarkable difference in
the size of the male and female.[65] Every one knows how the ears vary
in size in different breeds, and with their great development their
muscles become atrophied. Certain breeds of dogs are described as
having a deep furrow between the nostrils and lips. The caudal
vertebrae, according to F. Cuvier, on whose authority the two last
statements rest, vary in number; and the tail in shepherd dogs is
almost absent. The mammae vary from seven to ten in number; Daubenton,
having examined twenty-one dogs, found eight with five mammae on each
side; eight with four on each side; and the others with an unequal
number on the two sides.[66] Dogs have properly five toes in front and
four behind, but a fifth toe is often added; and F. Cuvier states that,
when a fifth toe is present, a fourth cuneiform bone is developed; and,
in this case, sometimes the great cuneiform bone is raised, and gives
on its inner side a large articular surface to the astragalus; so that
even the relative connection of the bones, the most constant of all
characters, varies. These modifications, however, in the feet of dogs
are not important, because they ought to be ranked, as De Blainville
has shown,[67] as monstrosities. Nevertheless they are interesting from
being correlated with the size of the body, for they occur much more
frequently with mastiffs and other large breeds than with small dogs.
Closely allied varieties, however, sometimes differ in this respect;
thus Mr. Hodgson states that the black-and-tan Lassa variety of the
Thibet mastiff has the fifth digit, whilst the Mustang sub-variety is
not thus characterised. The extent to which the skin is developed
between the toes varies much; but we shall return to this point. The
degree to which the various breeds differ in the perfection of their
senses, dispositions, and inherited habits is notorious to every one.
The breeds present some constitutional differences: the pulse, says
Youatt,[68] "varies materially according to the breed, as well {36} as
to the size of the animal." Different breeds of dogs are subject in
different degrees to various diseases. They certainly become adapted to
different climates under which they have long existed. It is notorious
that most of our best European breeds deteriorate in India.[69] The
Rev. R. Everest[70] believes that no one has succeeded in keeping the
Newfoundland dog long alive in India; so it is, according to
Lichtenstein,[71] even at the Cape of Good Hope. The Thibet mastiff
degenerates on the plains of India, and can live only on the
mountains.[72] Lloyd[73] asserts that our bloodhounds and bulldogs have
been tried, and cannot withstand the cold of the northern European
forests.
Seeing in how many characters the races of the dog differ from each other,
and remembering Cuvier's admission that their skulls differ more than do
those of the species of any natural genus, and bearing in mind how closely
the bones of wolves, jackals, foxes, and other Canidae agree, it is
remarkable that we meet with the statement, repeated over and over again,
that the races of the dog differ in no important characters. A highly
competent judge, Prof. Gervais,[74] admits, "si l'on prenait sans controle
les alterations dont chacun de ces organes est susceptible, on pourrait
croire qu'il y a entre les chiens domestiques des differences plus grandes
que celles qui separent ailleurs les especes, quelquefois meme les genres."
Some of the differences above enumerated are in one respect of
comparatively little value, for they are not characteristic of distinct
breeds: no one pretends that such is the case with the additional molar
teeth or with the number of mammae; the additional digit is generally
present with mastiffs, and some of the more important differences in the
skull and lower jaw are more or less characteristic of various breeds. But
we must not forget that the predominant power of selection has not been
applied in any of these cases; we have variability in important parts, but
the differences have not been fixed by selection. Man {37} cares for the
form and fleetness of his greyhounds, for the size of his mastiffs, for the
strength of the jaw in his bulldogs, &c.; but he cares nothing about the
number of their molar teeth or mammae or digits; nor do we know that
differences in these organs are correlated with, or owe their development
to, differences in other parts of the body about which man does care. Those
who have attended to the subject of selection will admit that, nature
having given variability, man, if he so chose, could fix five toes to the
hinder feet of certain breeds of dogs, as certainly as to the feet of his
Dorking-fowls: he could probably fix, but with much more difficulty, an
additional pair of molar teeth in either jaw, in the same way as he has
given additional horns to certain breeds of sheep; if he wished to produce
a toothless breed of dogs, having the so-called Turkish dog with its
imperfect teeth to work on, he could probably do so, for he has succeeded
in making hornless breeds of cattle and sheep.
With respect to the precise causes and steps by which the several races of
dogs have come to differ so greatly from each other, we are, as in most
other cases, profoundly ignorant. We may attribute part of the difference
in external form and constitution to inheritance from distinct wild stocks,
that is to changes effected under nature before domestication. We must
attribute something to the crossing of the several domestic and natural
races. I shall, however, soon recur to the crossing of races. We have
already seen how often savages cross their dogs with wild native species;
and Pennant gives a curious account[75] of the manner in which Fochabers,
in Scotland, was stocked "with a multitude of curs of a most wolfish
aspect" from a single hybrid-wolf brought into that district.
It would appear that climate to a certain extent directly modifies the
forms of dogs. We have lately seen that several of our English breeds
cannot live in India, and it is positively asserted that when bred there
for a few generations they degenerate not only in their mental faculties,
but in form. Captain Williamson,[76] who carefully attended to this
subject, states that "hounds are the most rapid in their decline;"
"greyhounds and {38} pointers, also, rapidly decline." But spaniels, after
eight or nine generations, and without a cross from Europe, are as good as
their ancestors. Dr. Falconer informs me that bulldogs, which have been
known, when first brought into the country, to pin down even an elephant by
its trunk, not only fall off after two of three generations in pluck and
ferocity, but lose the under-hung character of their lower jaws; their
muzzles become finer and their bodies lighter. English dogs imported into
India are so valuable that probably due care has been taken to prevent
their crossing with native dogs; so that the deterioration cannot be thus
accounted for. The Rev. R. Everest informs me that he obtained a pair of
setters, born in India, which perfectly resembled their Scotch parents: he
raised several litters from them in Delhi, taking the most stringent
precautions to prevent a cross, but he never succeeded, though this was
only the second generation in India, in obtaining a single young dog like
its parents in size or make; their nostrils were more contracted, their
noses more pointed, their size inferior, and their limbs more slender. This
remarkable tendency to rapid deterioration in European dogs subjected to
the climate of India, may perhaps partly be accounted for by the tendency
to reversion to a primordial condition which many animals exhibit, as we
shall see in a future chapter, when exposed to new conditions of life.
Some of the peculiarities characteristic of the several breeds of the dog
have probably arisen suddenly, and, though strictly inherited, may be
called monstrosities; for instance, the shape of the legs and body in the
turnspit of Europe and India; the shape of the head and the under-hanging
jaw in the bull and pug-dog, so alike in this one respect and so unlike in
all others. A peculiarity suddenly arising, and therefore in one sense
deserving to be called a monstrosity, may, however, be increased and fixed
by man's selection. We can hardly doubt that long-continued training, as
with the greyhound in coursing hares, as with water-dogs in swimming--and
the want of exercise, in the case of lapdogs--must have produced some
direct effect on their structure and instincts. But we shall immediately
see that the most potent cause of change has probably been the selection,
both methodical and unconscious, of slight individual differences,--the
{39} latter kind of selection resulting from the occasional preservation,
during hundreds of generations, of those individual dogs which were the
most useful to man for certain purposes and under certain conditions of
life. In a future chapter on Selection I shall show that even barbarians
attend closely to the qualities of their dogs. This unconscious selection
by man would lie aided by a kind of natural selection; for the dogs of
savages have partly to gain their own subsistence; for instance, in
Australia, as we hear from Mr. Nind,[77] the dogs are sometimes compelled
by want to leave their masters and provide for themselves; but in a few
days they generally return. And we may infer that dogs of different shapes,
sizes, and habits, would have best chance of surviving under different
circumstances,--on open, sterile plains, where they have to run down their
own prey,--on rocky coasts, where they have to feed on crabs and fish left
in the tidal pools, as in the case of New Guinea and Tierra del Fuego. In
this latter country, as I am informed by Mr. Bridges, the Catechist to the
Mission, the dogs turn over the stones on the shore to catch the
crustaceans which lie beneath, and they "are clever enough to knock off the
shell-fish at a first blow;" for if this be not done, shell-fish are well
known to have an almost invincible power of adhesion.
It has already been remarked that dogs differ in the degree to which their
feet are webbed. In dogs of the Newfoundland breed, which are eminently
aquatic in their habits, the skin, according to Isidore Geoffroy,[78]
extends to the third phalanges, whilst in ordinary dogs it extends only to
the second. In two Newfoundland dogs which I examined, when the toes were
stretched apart and viewed on the under side, the skin extended in a nearly
straight line between the outer margins of the balls of the toes; whereas,
in two terriers of distinct sub-breeds, the skin viewed in the same manner
was deeply scooped out. In Canada there is a dog which is peculiar to the
country and common there, and this has "half-webbed feet and is fond of the
water."[79] English otter-hounds are said to have webbed feet: a friend
examined for me the feet of two, in comparison {40} with the feet of some
harriers and bloodhounds; he found the skin variable in extent in all, but
more developed in the otter than in the other hounds.[80] As aquatic
animals which belong to quite different orders have webbed feet, there can
be no doubt that this structure would be serviceable to dogs that frequent
the water. We may confidently infer that no man ever selected his
water-dogs by the extent to which the skin was developed between their
toes; but what he does, is to preserve and breed from those individuals
which hunt best in the water, or best retrieve wounded game, and thus he
unconsciously selects dogs with feet slightly better webbed. Man thus
closely imitates Natural Selection. We have an excellent illustration of
this same process in North America, where, according to Sir J.
Richardson,[81] all the wolves, foxes, and aboriginal domestic dogs have
their feet broader than in the corresponding species of the Old World, and
"well calculated for running on the snow." Now, in these Arctic regions,
the life or death of every animal will often depend on its success in
hunting over the snow when softened; and this will in part depend on the
feet being broad; yet they must not be so broad as to interfere with the
activity of the animal when the ground is sticky, or with its power of
burrowing holes, or with other habits of life.
As changes in domestic breeds which take place so slowly as not to be
noticed at any one period, whether due to the selection of individual
variations or of differences resulting from crosses, are most important in
understanding the origin of our domestic productions, and likewise in
throwing indirect light on the changes effected under nature, I will give
in detail such cases as I have been able to collect. Lawrence,[82] who paid
particular attention to the history of the foxhound, writing in 1829, says
that between eighty and ninety years before "an entirely new foxhound was
raised through the breeder's art," the ears of the old southern hound being
reduced, the bone and bulk lightened, the waist increased in length, and
the stature {41} somewhat added to. It is believed that this was effected
by a cross with the greyhound. With respect to this latter dog, Youatt,[83]
who is generally cautious in his statements, says that the greyhound within
the last fifty years, that is before the commencement of the present
century, "assumed a somewhat different character from that which he once
possessed. He is now distinguished by a beautiful symmetry of form, of
which he could not once boast, and he has even superior speed to that which
he formerly exhibited. He is no longer used to struggle with deer, but
contends with his fellows over a shorter and speedier course." An able
writer[84] believes that our English greyhounds are the descendants,
_progressively improved_, of the large rough greyhounds which existed in
Scotland so early as the third century. A cross at some former period with
the Italian greyhound has been suspected; but this seems hardly probable,
considering the feebleness of this latter breed. Lord Orford, as is well
known, crossed his famous greyhounds, which failed in courage, with a
bulldog--this breed being-chosen from being deficient in the power of
scent; "after the sixth or seventh generation," says Youatt, "there was not
a vestige left of the form of the bulldog, but his courage and indomitable
perseverance remained."
Youatt infers, from a comparison of an old picture of King Charles's
spaniels with the living dog, that "the breed of the present day is
materially altered for the worse:" the muzzle has become shorter, the
forehead more prominent, and the eyes larger: the changes in this case have
probably been due to simple selection. The setter, as this author remarks
in another place, "is evidently the large spaniel improved to his present
peculiar size and beauty, and taught another way of marking his game. If
the form of the dog were not sufficiently satisfactory on this point, we
might have recourse to history:" he then refers to a document dated 1685
bearing on this subject, and adds that the pure Irish setter shows no signs
of a cross with the pointer, which some authors suspect has been the case
with the English setter. Another writer[85] remarks {42} that, if the
mastiff and English bulldog had formerly been as distinct as they are at
the present time (_i.e._ 1828), so accurate an observer as the poet Gay
(who was the author of 'Rural Sports' in 1711) would have spoken in his
Fable of the _Bull and the Bulldog_, and not of the _Bull and the Mastiff_.
There can be no doubt that the fancy bulldogs of the present day, now that
they are not used for bull-baiting, have become greatly reduced in size,
without any express intention on the part of the breeder. Our pointers are
certainly descended from a Spanish breed, as even their names, Don, Ponto,
Carlos, &c., would show: it is said that they were not known in England
before the Revolution in 1688;[86] but the breed since its introduction has
been much modified, for Mr. Borrow, who is a sportsman and knows Spain
intimately well, informs me that he has not seen in that country any breed
"corresponding in figure with the English pointer; but there are genuine
pointers near Xeres which have been imported by English gentlemen." A
nearly parallel case is offered by the Newfoundland dog, which was
certainly brought into England from that country, but which has since been
so much modified that, as several writers have observed, it does not now
closely resemble any existing native dog in Newfoundland.[87]
These several cases of slow and gradual changes in our English dogs possess
some interest; for though the changes have generally, but not invariably,
been caused by one or two crosses with a distinct breed, yet we may feel
sure, from the well-known extreme variability of crossed breeds, that
rigorous and long-continued selection must have been practised, in order to
improve them in a definite manner. As soon as any strain or family became
slightly improved or better adapted to altered circumstances, it would tend
to supplant the older and less improved strains. For instance, as soon as
the old foxhound was improved by a cross with the greyhound, or by simple
selection, and assumed its present character--and the change was probably
required by {43} the increased fleetness of our hunters--it rapidly spread
throughout the country, and is now everywhere nearly uniform. But the
process of improvement is still going on, for every one tries to improve
his strain by occasionally procuring dogs from the best kennels. Through
this process of gradual substitution the old English hound has been lost;
and so it has been with the old Irish greyhound and apparently with the old
English bulldog. But the extinction of former breeds is apparently aided by
another cause; for whenever a breed is kept in scanty numbers, as at
present with the bloodhound, it is reared with difficulty, and this
apparently is due to the evil effects of long-continued close
interbreeding. As several breeds of the dog have been slightly but sensibly
modified within so short a period as the last one or two centuries, by the
selection of the best individual dogs, modified in many cases by crosses
with other breeds; and as we shall hereafter see that the breeding of dogs
was attended to in ancient times, as it still is by savages, we may
conclude that we have in selection, even if only occasionally practised, a
potent means of modification.
DOMESTIC CATS.
Cats have been domesticated in the East from an ancient period; Mr. Blyth
informs me that they are mentioned in a Sanskrit writing 2000 years old,
and in Egypt their antiquity is known to be even greater, as shown by
monumental drawings and their mummied bodies. These mummies, according to
De Blainville[88] who has particularly studied the subject, belong to no
less than three species, namely, _F. caligulata_, _bubastes_, and _chaus_.
The two former species are said to be still found, both wild and
domesticated, in parts of Egypt. _F. caligulata_ presents a difference in
the first inferior milk molar tooth, as compared with the domestic cats of
Europe, which makes De Blainville conclude that it is not one of the
parent-forms of our cats. Several naturalists, as Pallas, Temminck, Blyth,
believe that domestic cats are the descendants of several species {44}
commingled: it is certain that cats cross readily with various wild
species, and it would appear that the character of the domestic breeds has,
at least in some cases, been thus affected. Sir W. Jardine has no doubt
that, "in the north of Scotland, there has been occasional crossing with
our native species (_F. sylvestris_), and that the result of these crosses
has been kept in our houses. I have seen," he adds, "many cats very closely
resembling the wild cat, and one or two that could scarcely be
distinguished from it." Mr. Blyth[89] remarks on this passage, "but such
cats are never seen in the southern parts of England; still, as compared
with any Indian tame cat, the affinity of the ordinary British cat to _F.
sylvestris_ is manifest; and due I suspect to frequent intermixture at a
time when the tame cat was first introduced into Britain and continued
rare, while the wild species was far more abundant than at present." In
Hungary, Jeitteles[90] was assured on trustworthy authority that a wild
male cat crossed with a female domestic cat, and that the hybrids long
lived in a domesticated state. In Algiers the domestic cat has crossed with
the wild cat (_F. Lybica_) of that country.[91] In South Africa, as Mr. E.
Layard informs me, the domestic cat intermingles freely with the wild _F.
caffra_; he has seen a pair of hybrids which were quite tame and
particularly attached to the lady who brought them up; and Mr. Fry has
found that these hybrids are fertile. In India the domestic cat, according
to Mr. Blyth, has crossed with four Indian species. With respect to one of
these species, _F. chaus_, an excellent observer, Sir W. Elliot, informs me
that he once killed, near Madras, a wild brood, which were evidently
hybrids from the domestic cat; these young animals had a thick lynx-like
tail and the broad brown bar on the inside of the forearm characteristic of
_F. chaus_. Sir W. Elliot adds that he has often observed this same mark on
the forearms of domestic cats in India. Mr. Blyth states that domestic cats
coloured nearly like _F. chaus_, but not resembling that species in shape,
abound in {45} Bengal; he adds, "such a colouration is utterly unknown in
European cats, and the proper tabby markings (pale streaks on a black
ground, peculiarly and symmetrically disposed), so common in English cats,
are never seen in those of India." Dr. D. Short has assured Mr. Blyth[92]
that at Hansi hybrids between the common cat and _F. ornata_ (or
_torquata_) occur, "and that many of the domestic cats of that part of
India were undistinguishable from the wild _F. ornata_." Azara states, but
only on the authority of the inhabitants, that in Paraguay the cat has
crossed with two native species. From these several cases we see that in
Europe, Asia, Africa, and America, the common cat, which lives a freer life
than most other domesticated animals, has crossed with various wild
species; and that in some instances the crossing has been sufficiently
frequent to affect the character of the breed.
Whether domestic cats have descended from several distinct species, or have
only been modified by occasional crosses, their fertility, as far as is
known, is unimpaired. The large Angora or Persian cat is the most distinct
in structure and habits of all the domestic breeds; and is believed by
Pallas, but on no distinct evidence, to be descended from the _F. manul_ of
middle Asia; but I am assured by Mr. Blyth that this cat breeds freely with
Indian cats, which, as we have already seen, have apparently been much
crossed with _F. chaus_. In England half-bred Angora cats are perfectly
fertile with the common cat; I do not know whether the half-breeds are
fertile one with another; but as they are common in some parts of Europe,
any marked degree of sterility could hardly fail to have been noticed.
Within the same country we do not meet with distinct races of the cat, as
we do of dogs and of most other domestic animals; though the cats of the
same country present a considerable amount of fluctuating variability. The
explanation obviously is that, from their nocturnal and rambling habits,
indiscriminate crossing cannot without much trouble be prevented. Selection
cannot be brought into play to produce distinct breeds, or to keep those
distinct which have been imported from foreign lands. On the other hand, in
islands and {46} in countries completely separated from each other, we meet
with breeds more or less distinct; and these cases are worth giving as
showing that the scarcity of distinct races in the same country is not
caused by a deficiency of variability in the animal. The tail-less cats of
the Isle of Man are said to differ from common cats not only in the want of
a tail, but in the greater length of their hind legs, in the size of their
heads, and in habits. The Creole cat of Antigua, as I am informed by Mr.
Nicholson, is smaller, and has a more elongated head, than the British cat.
In Ceylon, as Mr. Thwaites writes to me, every one at first notices the
different appearance of the native cat from the English animal; it is of
small size, with closely lying hairs; its head is small, with a receding
forehead; but the ears are large and sharp; altogether it has what is there
called a "low-caste" appearance. Rengger[93] says that the domestic cat,
which has been bred for 300 years in Paraguay, presents a striking
difference from the European cat; it is smaller by a fourth, has a more
lanky body, its hair is short, shining, scanty, and lies close, especially
on the tail: he adds that the change has been less at Ascension, the
capital of Paraguay, owing to the continual crossing with newly imported
cats; and this fact well illustrates the importance of separation. The
conditions of life in Paraguay appear not to be highly favourable to the
cat, for, though they have run half-wild, they do not become thoroughly
feral, like so many other European animals. In another part of South
America, according to Roulin,[94] the introduced cat has lost the habit of
uttering its hideous nocturnal howl. The Rev. W. D. Fox purchased a cat in
Portsmouth, which he was told came from the coast of Guinea; its skin was
black and wrinkled, fur bluish-grey and short, its ears rather bare, legs
long, and whole aspect peculiar. This "negro" cat was fertile with common
cats. On the opposite coast of Africa, at Mombas, Captain Owen, R.N.,[95]
states that all the cats are covered with short stiff hair instead of fur:
he gives a curious account of a cat from Algoa Bay, which had been kept for
some time on board and could be identified with certainty; this {47} animal
was left for only eight weeks at Mombas, but during that short period it
"underwent a complete metamorphosis, having parted with its sandy-coloured
fur." A cat from the Cape of Good Hope has been described by Desmarest as
remarkable from a red stripe extending along the whole length of its back.
Throughout an immense area, namely, the Malayan archipelago, Siam, Pegu,
and Burmah, all the cats have truncated tails about half the proper
length,[96] often with a sort of knot at the end. In the Caroline
archipelago the cats have very long legs, and are of a reddish-yellow
colour.[97] In China a breed has drooping ears. At Tobolsk, according to
Gmelin, there is a red-coloured breed. In Asia, also, we find the
well-known Angora or Persian breed.
The domestic cat has run wild in several countries, and everywhere assumes,
as far as can be judged by the short recorded descriptions, a uniform
character. Near Maldonado, in La Plata, I shot one which seemed perfectly
wild; it was carefully examined by Mr. Waterhouse,[98] who found nothing
remarkable in it, excepting its great size. In New Zealand, according to
Dieffenbach, the feral cats assume a streaky grey colour like that of wild
cats; and this is the case with the half-wild cats of the Scotch Highlands.
We have seen that distant countries possess distinct domestic races of the
cat. The differences may be in part due to descent from several aboriginal
species, or at least to crosses with them. In some cases, as in Paraguay,
Mombas, and Antigua, the differences seem due to the direct action of
different conditions of life. In other cases some slight effect may
possibly be attributed to natural selection, as cats in many cases have
largely to support themselves and to escape diverse dangers. But man, owing
to the difficulty of pairing cats, has done nothing by methodical
selection; and probably very little by unintentional selection; though in
each litter he generally saves the prettiest, {48} and values most a good
breed of mouse or rat-catchers. Those cats which have a strong tendency to
prowl after game, generally get destroyed by traps. As cats are so much
petted, a breed bearing the same relation to other cats, that lapdogs bear
to larger dogs, would have been much valued; and if selection could have
been applied, we should certainly have had many breeds in each
long-civilized country, for there is plenty of variability to work upon.
We see in this country considerable diversity in size, some in the
proportions of the body, and extreme variability in colouring. I have only
lately attended to this subject, but have already heard of some singular
cases of variation; one of a cat born in the West Indies toothless, and
remaining so all its life. Mr. Tegetmeier has shown me the skull of a
female cat with its canines so much developed that they protruded uncovered
beyond the lips; the tooth with the fang being .95, and the part projecting
from the gum .6 of an inch in length. I have heard of a family of six-toed
cats. The tail varies greatly in length; I have seen a cat which always
carried its tail flat on its back when pleased. The ears vary in shape, and
certain strains, in England, inherit a pencil-like tuft of hairs, above a
quarter of an inch in length, on the tips of their ears; and this same
peculiarity, according to Mr. Blyth, characterises some cats in India. The
great variability in the length of the tail and the lynx-like tufts of
hairs on the ears are apparently analogous to differences in certain wild
species of the genus. A much more important difference, according to
Daubenton,[99] is that the intestines of domestic cats are wider, and a
third longer, than in wild cats of the same size; and this apparently has
been caused by their less strictly carnivorous diet.
* * * * *
{49}
CHAPTER II.
HORSES AND ASSES.
HORSE.--DIFFERENCES IN THE BREEDS--INDIVIDUAL VARIABILITY OF--DIRECT
EFFECTS OF THE CONDITIONS OF LIFE--CAN WITHSTAND MUCH COLD--BREEDS MUCH
MODIFIED BY SELECTION--COLOURS OF THE HORSE--DAPPLING--DARK STRIPES ON
THE SPINE, LEGS, SHOULDERS, AND FOREHEAD--DUN-COLOURED HORSES MOST
FREQUENTLY STRIPED--STRIPES PROBABLY DUE TO REVERSION TO THE PRIMITIVE
STATE OF THE HORSE.
ASSES.--BREEDS OF--COLOUR OF--LEG- AND SHOULDER-
STRIPES--SHOULDER-STRIPES SOMETIMES ABSENT, SOMETIMES FORKED.
The history of the Horse is lost in antiquity. Remains of this animal in a
domesticated condition have been found in the Swiss lake-dwellings,
belonging to the latter part of the Stone period.[100] At the present time
the number of breeds is great, as may be seen by consulting any treatise on
the Horse.[101] Looking only to the native ponies of Great Britain, those
of the Shetland Isles, Wales, the New Forest, and Devonshire are
distinguishable; and so it is with each separate island in the great Malay
archipelago.[102] Some of the breeds present great differences in size,
shape of ears, length of mane, proportions of the body, form of the withers
and hind quarters, and especially in the head. Compare the race-horse,
dray-horse, and a Shetland pony in size, configuration, and disposition;
and see how much greater the difference is than between the six or seven
other living species of the genus Equus.
{50}
Of individual variations not known to characterise particular breeds, and
not great or injurious enough to be called monstrosities, I have not
collected many cases. Mr. G. Brown, of the Cirencester Agricultural
College, who has particularly attended to the dentition of our domestic
animals, writes to me that he has "several times noticed eight permanent
incisors instead of six in the jaw." Male horses alone properly have
canines, but they are occasionally found in the mare, though of small
size.[103] The number of ribs is properly eighteen, but Youatt[104] asserts
that not unfrequently there are nineteen on each side, the additional one
being always the posterior rib. I have seen several notices of variations
in the bones of the leg; thus Mr. Price[105] speaks of an additional bone
in the hock, and of certain abnormal appearances between the tibia and
astragalus, as quite common in Irish horses, and not due to disease. Horses
have often been observed, according to M. Gaudry,[106] to possess a
trapezium and a rudiment of a fifth metacarpal bone, so that "one sees
appearing by monstrosity, in the foot of the horse, structures which
normally exist in the foot of the Hipparion,"--an allied and extinct
animal. In various countries horn-like projections have been observed on
the frontal bones of the horse: in one case described by Mr. Percival they
arose about two inches above the orbital processes, and were "very like
those in a calf from five to six months old," being from half to
three-quarters of an inch in length.[107] Azara has described two cases in
South America in which the projections were between three and four inches
in length: other instances have occurred in Spain.
That there has been much inherited variation in the horse cannot be
doubted, when we reflect on the number of the breeds existing throughout
the world or even within the same country, and when we know that they have
largely increased in number {51} since the earliest known records.[108]
Even in so fleeting a character as colour, Hofacker[109] found that, out of
two hundred and sixteen cases in which horses of the same colour were
paired, only eleven pairs produced foals of a quite different colour. As
Professor Low[110] has remarked, the English race-horse offers the best
possible evidence of inheritance. The pedigree of a race-horse is of more
value in judging of its probable success than its appearance: "King Herod"
gained in prizes 201,505l. sterling, and begot 497 winners; "Eclipse" begot
334 winners.
Whether the whole amount of difference between the various breeds be due to
variation is doubtful. From the fertility of the most distinct breeds[111]
when crossed, naturalists have generally looked at all the breeds as having
descended from a single species. Few will agree with Colonel H. Smith, who
believes that they have descended from no less than five primitive and
differently coloured stocks.[112] But as several species and varieties of
the horse existed[113] during the later tertiary periods, and as Ruetimeyer
found differences in the size and form of the skull in the earliest known
domesticated horses,[114] we ought not to feel sure that all our breeds
have descended from a single species. As we see that the savages of North
and South America easily reclaim the feral horses, there is no
improbability in savages in various quarters of the world having
domesticated more than one native species or natural race. No aboriginal or
truly wild horse is positively known now to exist; for it is thought by
some authors that the wild horses of the East are escaped domestic
animals.[115] If our domestic breeds have descended from several {52}
species or natural races, these apparently have all become extinct in the
wild state. With our present knowledge, the common view that all have
descended from a single species is, perhaps, the most probable.
With respect to the causes of the modifications which horses have
undergone, the conditions of life seem to produce a considerable direct
effect. Mr. D. Forbes, who has had excellent opportunities of comparing the
horses of Spain with those of South America, informs me that the horses of
Chile, which have lived under nearly the same conditions as their
progenitors in Andalusia, remain unaltered, whilst the Pampas horses and
the Puno ponies are considerably modified. There can be no doubt that
horses become greatly reduced in size and altered in appearance by living
on mountains and islands; and this apparently is due to want of nutritious
or varied food. Every one knows how small and rugged the ponies are on the
Northern islands and on the mountains of Europe. Corsica and Sardinia have
their native ponies; and there were,[116] or still are, on some islands on
the coast of Virginia, ponies like those of the Shetland Islands, which are
believed to have originated through exposure to unfavourable conditions.
The Puno ponies, which inhabit the lofty regions of the Cordillera, are, as
I hear from Mr. D. Forbes, strange little creatures, very unlike their
Spanish progenitors. Further south, in the Falkland Islands, the offspring
of the horses imported in 1764 have already so much deteriorated in
size[117] and strength that they are unfitted for catching wild cattle with
the lasso; so that fresh horses have to be brought for this purpose from La
Plata at a great expense. The reduced size of the horses bred on both
southern and northern islands, and on several mountain-chains, can hardly
have been caused by the cold, as a similar reduction has occurred on the
Virginian and Mediterranean islands. The horse can withstand intense cold,
for wild troops live on the plains of Siberia under lat. 56 deg.,[118] and
aboriginally the horse must {53} have inhabited countries annually covered
with snow, for he long retains the instinct of scraping it away to get at
the herbage beneath. The wild tarpans in the East have this instinct; and,
as I am informed by Admiral Sulivan, this is likewise the case with the
horses which have run wild on the Falkland Islands; now this is the more
remarkable as the progenitors of these horses could not have followed this
instinct during many generations in La Plata: the wild cattle of the
Falklands never scrape away the snow, and perish when the ground is long
covered. In the northern parts of America the horses, descended from those
introduced by the Spanish conquerors of Mexico, have the same habit, as
have the native bisons, but not so the cattle introduced from Europe.[119]
The horse can flourish under intense heat as well as under intense cold,
for he is known to come to the highest perfection, though not attaining a
large size, in Arabia and northern Africa. Much humidity is apparently more
injurious to the horse than heat or cold. In the Falkland Islands, horses
suffer much from the dampness; and this same circumstance may perhaps
partly account for the singular fact that to the eastward of the Bay of
Bengal,[120] over an enormous and humid area, in Ava, Pegu, Siam, the
Malayan archipelago, the Loo Choo Islands, and a large part of China, no
full-sized horse is found. When we advance as far eastward as Japan, the
horse reacquires his full size.[121]
With most of our domesticated animals, some breeds are kept on account of
their curiosity or beauty; but the horse is valued almost solely for its
utility. Hence semi-monstrous breeds are not preserved; and probably all
the existing breeds have been slowly formed either by the direct action of
the conditions of life, or through the selection of individual differences.
No doubt semi-monstrous breeds might have been formed: thus Mr. Waterton
records[122] the case of a mare which produced {54} successively three
foals without tails; so that a tailless race might have been formed like
the tailless races of dogs and cats. A Russian breed of horses is said to
have frizzled hair, and Azara[123] relates that in Paraguay horses are
occasionally born, but are generally destroyed, with hair like that on the
head of a negro; and this peculiarity is transmitted even to half-breeds:
it is a curious case of correlation that such horses have short manes and
tails, and their hoofs are of a peculiar shape like those of a mule.
It is scarcely possible to doubt that the long-continued selection of
qualities serviceable to man has been the chief agent in the formation of
the several breeds of the horse. Look at a dray-horse, and see how well
adapted he is to draw heavy weights, and how unlike in appearance to any
allied wild animal. The English race-horse is known to have proceeded from
the commingled blood of Arabs, Turks, and Barbs; but selection and training
have together made him a very different animal from his parent-stocks. As a
writer in India, who evidently knows the pure Arab well, asks, who now,
"looking at our present breed of race-horses, could have conceived that
they were the result of the union of the Arab horse and African mare?" The
improvement is so marked that in running for the Goodwood Cup "the first
descendants of Arabian, Turkish, and Persian horses, are allowed a discount
of 18 lbs. weight; and when both parents are of these countries a discount
of 36 lbs."[124] It is notorious that the Arabs have long been as careful
about the pedigree of their horses as we are, and this implies great and
continued care in breeding. Seeing what has been done in England by careful
breeding, can we doubt that the Arabs must likewise have produced during
the course of centuries a marked effect on the qualities of their horses?
But we may go much farther back in time, for in the most ancient known
book, the Bible, we hear of studs carefully kept for breeding, {55} and of
horses imported at high prices from various countries.[125] We may
therefore conclude that, whether or not the various existing breeds of the
horse have proceeded from one or more aboriginal stocks, yet that a great
amount of change has resulted from the direct action of the conditions of
life, and probably a still greater amount from the long-continued selection
by man of slight individual differences.
With several domesticated quadrupeds and birds, certain coloured marks are
either strongly inherited or tend to reappear after having long been lost.
As this subject will hereafter be seen to be of importance, I will give a
full account of the colouring of horses. All English breeds, however unlike
in size and appearance, and several of those in India and the Malay
archipelago, present a similar range and diversity of colour. The English
race-horse, however, is said[126] never to be dun-coloured; but as dun and
cream-coloured horses are considered by the Arabs as worthless, "and fit
only for Jews to ride,"[127] these tints may have been removed by
long-continued selection. Horses of every colour, and of such widely
different kinds as dray-horses, cobs, and ponies, are all occasionally
dappled,[128] in the same manner as is so conspicuous with grey horses.
This fact does not throw any clear light on the colouring of the aboriginal
horse, but is a case of analogous variation, for even asses are sometimes
dappled, and I have seen, in the British Museum, a hybrid from the ass and
zebra dappled on its hinder quarters. By the expression analogous variation
(and it is one that I shall often have occasion to use) I mean a variation
occurring in a species or variety which resembles a normal character in
another and distinct species or variety. Analogous variations may arise, as
will be explained in a future chapter, {56} from two or more forms with a
similar constitution having been exposed to similar conditions,--or from
one of two forms having reacquired through reversion a character inherited
by the other form from their common progenitor,--or from both forms having
reverted to the same ancestral character. We shall immediately see that
horses occasionally exhibit a tendency to become striped over a large part
of their bodies; and as we know that stripes readily pass into spots and
cloudy marks in the varieties of the domestic cat and in several feline
species--even the cubs of the uniformly-coloured lion being spotted with
dark marks on a lighter ground--we may suspect that the dappling of the
horse, which has been noticed by some authors with surprise, is a
modification or vestige of a tendency to become striped.
[Illustration: Fig. 1.--Dun Devonshire Pony, with shoulder, spinal, and leg
stripes.]
This tendency in the horse to become striped is in several respects an
interesting feet. Horses of all colours, of the most diverse breeds, in
various parts of the world, often have a dark stripe extending along
the spine, from the mane to the tail; but this is so common that I need
enter into no particulars.[129] Occasionally horses are transversely
barred on the legs, chiefly on the under side; and more rarely they
have a distinct stripe on the shoulder, like that on the shoulder of
the ass, or a broad dark patch representing a stripe. Before entering
on any details I must premise that {57} the term dun-coloured is vague,
and includes three groups of colour, viz. that between cream-colour and
reddish-brown, which graduates into light-bay or light-chesnut--this, I
believe, is often called fallow-dun; secondly, leaden or slate-colour
or mouse-dun, which graduates into an ash-colour; and, lastly,
dark-dun, between brown and black. In England I have examined a rather
large, lightly-built, fallow-dun Devonshire pony (fig. 1), with a
conspicuous stripe along the back, with light transverse stripes on the
under sides of its front legs, and with four parallel stripes on each
shoulder. Of these four stripes the posterior one was very minute and
faint; the anterior one, on the other hand, was long and broad, but
interrupted in the middle, and truncated at its lower extremity, with
the anterior angle produced into a long tapering point. I mention this
latter fact because the shoulder-stripe of the ass occasionally
presents exactly the same appearance. I have had an outline and
description sent to me of a small, purely-bred, light fallow-dun Welch
pony, with a spinal stripe, a single transverse stripe on each leg, and
three shoulder-stripes; the posterior stripe corresponding with that on
the shoulder of the ass was the longest, whilst the two anterior
parallel stripes, arising from the mane, decreased in length, in a
reversed manner as compared with the shoulder-stripes on the
above-described Devonshire pony. I have seen a bright fallow-dun,
strong cob, with its front legs transversely barred on the under sides
in the most conspicuous manner; also a dark-leaden mouse-coloured pony
with similar leg stripes, but much less conspicuous; also a bright
fallow-dun colt, fully three-parts thoroughbred, with very plain
transverse stripes on the legs; also a chesnut-dun cart-horse with a
conspicuous spinal stripe, with distinct traces of shoulder-stripes,
but none on the legs; I could add other cases. My son made a sketch for
me of a large, heavy, Belgian cart-horse, of a fallow-dun, with a
conspicuous spinal stripe, traces of leg-stripes, and with two parallel
(three inches apart) stripes about seven or eight inches in length on
both shoulders. I have seen another rather light cart-horse, of a dirty
dark cream-colour, with striped legs, and on one shoulder a large
ill-defined dark cloudy patch, and on the opposite shoulder two
parallel faint stripes. All the cases yet mentioned are duns of various
tints; but Mr. W. W. Edwards has seen a nearly thoroughbred chesnut
horse which had the spinal stripe, and distinct bars on the legs; and I
have seen two bay carriage-horses with black spinal stripes; one of
these horses had on each shoulder a light shoulder-stripe, and the
other had a broad black ill-defined stripe, running obliquely half-way
down each shoulder; neither had leg-stripes.
The most interesting case which I have met with occurred in a colt of
my own breeding. A bay mare (descended from a dark-brown Flemish mare
by a light grey Turcoman horse) was put to Hercules, a thoroughbred
dark bay, whose sire (Kingston) and dam were both bays. The colt
ultimately turned out brown; but when only a fortnight old it was a
dirty bay, shaded with mouse-grey, and in parts with a yellowish tint:
it had only a trace of the spinal stripe, with a few obscure transverse
bars on the legs; but almost the whole body was marked with very narrow
dark stripes, in most parts so obscure as to be visible only in certain
lights, like the {58} stripes which may be seen on black kittens. These
stripes were distinct on the hind-quarters, where they diverged from
the spine, and pointed a little forwards; many of them as they diverged
from the spine became a little branched, exactly in the same manner as
in some zebrine species. The stripes were plainest on the forehead
between the ears, where they formed a set of pointed arches, one under
the other, decreasing in size downwards towards the muzzle; exactly
similar marks may be seen on the forehead of the quagga and Burchell's
zebra. When this foal was two or three months old all the stripes
entirely disappeared. I have seen similar marks on the forehead of a
fully grown, fallow-dun, cob-like horse, having a conspicuous spinal
stripe, and with its front legs well barred.
In Norway the colour of the native horse or pony is dun, varying from
almost cream-colour to dark mouse-dun; and an animal is not considered
purely bred unless it has the spinal and leg stripes.[130] In one part
of the country my son estimated that about a third of the ponies had
striped legs; he counted seven stripes on the fore-legs and two on the
hind-legs of one pony; only a few of them exhibited traces of
shoulder-stripes; but I have heard of a cob imported from Norway which
had the shoulder as well as the other stripes well developed. Colonel
Ham. Smith[131] alludes to dun-horses with the spinal stripe in the
Sierras of Spain; and the horses originally derived from Spain, in some
parts of South America, are now duns. Sir W. Elliot informs me that he
inspected a herd of 300 South American horses imported into Madras, and
many of these had transverse stripes on the legs and short
shoulder-stripes; the most strongly marked individual, of which a
coloured drawing was sent me, was a mouse-dun, with the
shoulder-stripes slightly forked.
In the North-Western parts of India striped horses of more than one
breed are apparently commoner than in any other part of the world; and
I have received information respecting them from several officers,
especially from Colonel Poole, Colonel Curtis, Major Campbell,
Brigadier St. John, and others. The Kattywar horses are often fifteen
or sixteen hands in height, and are well but lightly built. They are of
all colours, but the several kinds of duns prevail; and these are so
generally striped, that a horse without stripes is not considered pure.
Colonel Poole believes that all the duns have the spinal stripe, the
leg-stripes are generally present, and he thinks that about half the
horses have the shoulder-stripe; this stripe is sometimes double or
treble on both shoulders. Colonel Poole has often seen stripes on the
cheeks and sides of the nose. He has seen stripes on the grey and bay
Kattywars when first foaled, but they soon faded away. I have received
other accounts of cream-coloured, bay, brown, and grey Kattywar horses
being striped. Eastward of India, the Shan (north of Burmah) ponies, as
I am informed by Mr. Blyth, have spinal, leg, and shoulder stripes. Sir
W. Elliot informs me that he saw two bay Pegu ponies with {59}
leg-stripes. Burmese and Javanese ponies are frequently dun-coloured,
and have the three kinds of stripes, "in the same degree as in
England."[132] Mr. Swinhoe informs me that he examined two light-dun
ponies of two Chinese breeds, viz. those of Shangai and Amoy; both had
the spinal stripe, and the latter an indistinct shoulder-stripe.
We thus see that in all parts of the world breeds of the horse as
different as possible, when of a dun-colour (including under this term
a wide range of tint from cream to dusky black), and rarely when of
bay, grey, and chesnut shades, have the several above-specified
stripes. Horses which are of a yellow colour with white mane and tail,
and which are sometimes called duns, I have never seen with
stripes.[133]
From reasons which will be apparent in the chapter on Reversion, I have
endeavoured, but with poor success, to discover whether duns, which are
so much oftener striped than other coloured horses, are ever produced
from the crossing of two horses, neither of which are duns. Most
persons to whom I have applied believe that one parent must be a dun;
and it is generally asserted, that, when this is the case, the
dun-colour and the stripes are strongly inherited.[134] One case has
fallen under my own observation of a foal from a black mare by a bay
horse, which when fully grown was a dark fallow-dun and had a narrow
but plain spinal stripe. Hofacker[135] gives two instances of
mouse-duns (Mausrapp) being produced from two parents of different
colours and neither duns.
I have also endeavoured with little success to find out whether the
stripes are generally plainer or less plain in the foal than in the
adult horse. Colonel Poole informs me that, as he believes, "the
stripes are plainest when the colt is first foaled; they then become
less and less distinct till after the first coat is shed, when they
come out as strongly as before; but certainly often fade away as the
age of the horse increases." Two other accounts confirm this fading of
the stripes in old horses in India. One writer, on the other hand,
states that colts are often born without stripes, but that they appear
as the colt grows older. Three authorities affirm that in Norway the
stripes are less plain in the foal than in the adult. Perhaps there is
no fixed rule. In the case described by me of the young foal which was
narrowly striped over nearly all its body, there was no doubt about the
the early and complete disappearance of the stripes. Mr. W. W. Edwards
examined for me twenty-two foals of race-horses, and twelve had the
spinal stripe more or less plain; this fact, and some other accounts
which I have received, lead me to believe that the spinal stripe often
disappears in the English race-horse when old. On the whole I infer
that the stripes are generally plainest in the foal, and tend to
disappear in old age.
The stripes are variable in colour, but are always darker than the rest of
the body. They do not by any means always {60} coexist on the different
parts of the body: the legs may be striped without any shoulder-stripe, or
the converse case, which is rarer, may occur; but I have never heard of
either shoulder or leg-stripes without the spinal stripe. The latter is by
far the commonest of all the stripes, as might have been expected, as it
characterises the other seven or eight species of the genus. It is
remarkable that so trifling a character as the shoulder-stripe being double
or triple should occur in such different breeds as Welch and Devonshire
ponies, the Shan pony, heavy cart-horses, light South American horses, and
the lanky Kattywar breed. Colonel Hamilton Smith believes that one of his
five supposed primitive stocks was dun-coloured and striped; and that the
stripes in all the other breeds result from ancient crosses with this one
primitive dun; but it is extremely improbable that different breeds living
in such distant quarters of the world should all have been crossed with any
one aboriginally distinct stock. Nor have we any reason to believe that the
effects of a cross at a very remote period could be propagated for so many
generations as is implied on this view.
With respect to the primitive colour of the horse having been dun, Colonel
Hamilton Smith[136] has collected a large body of evidence showing that
this tint was common in the East as far back as the time of Alexander, and
that the wild horses of Western Asia and Eastern Europe now are, or
recently were, of various shades of dun. It seems that not very long ago a
wild breed of dun-coloured horses with a spinal stripe was preserved in the
royal parks in Prussia. I hear from Hungary that the inhabitants of that
country look at the duns with a spinal stripe as the aboriginal stock, and
so it is in Norway. Dun-coloured ponies are not rare in the mountainous
parts of Devonshire, Wales, and Scotland, where the aboriginal breed would
have had the best chance of being preserved. In South America in the time
of Azara, when the horse had been feral for about 250 years, 90 out of 100
horses were "bai-chatains," and the remaining ten were "zains," and not
more than one in 2000 {61} black. Zain is generally translated as dark
without any white; but as Azara speaks of mules being "zain-clair," I
suspect that zain must have meant dun-coloured. In some parts of the world
feral horses show a strong tendency to become roans.[137]
In the following chapters on the Pigeon we shall see that in pure breeds of
various colours, when a blue bird is occasionally produced, certain black
marks invariably appear on the wings and tail; so again, when variously
coloured breeds are crossed, blue birds with the same black marks are
frequently produced. We shall further see that these facts are explained
by, and afford strong evidence in favour of, the view that all the breeds
are descended from the rock-pigeon, or _Columba livia_, which is thus
coloured and marked. But the appearance of the stripes on the various
breeds of the horse, when of a dun-colour, does not afford nearly such good
evidence of their descent from a single primitive stock as in the case of
the pigeon; because no certainly wild horse is known as a standard of
comparison; because the stripes when they do appear are variable in
character; because there is far from sufficient evidence of the appearance
of the stripes from the crossing of distinct breeds; and lastly, because
all the species of the genus Equus have the spinal stripe, and several have
shoulder and leg stripes. Nevertheless the similarity in the most distinct
breeds in their general range of colour, in their dappling, and in the
occasional appearance, especially in duns, of leg-stripes and of double or
triple shoulder-stripes, taken together, indicate the probability of the
descent of all the existing races from a single, dun-coloured, more or less
striped, primitive stock, to which our horses still occasionally revert.
{62}
THE ASS.
Four species of Asses, besides three of zebras, have been described by
naturalists; but there can now be little doubt that our domesticated animal
is descended from one alone, namely, the _Asinus taeniopus_ of
Abyssinia.[138] The ass is sometimes advanced as an instance of an animal
domesticated, as we know by the Old Testament, from an ancient period,
which has varied only in a very slight degree. But this is by no means
strictly true; for in Syria alone there are four breeds;[139] first, a
light and graceful animal, with an agreeable gait, used by ladies;
secondly, an Arab breed reserved exclusively for the saddle; thirdly, a
stouter animal used for ploughing and various purposes; and lastly, the
large Damascus breed, with a peculiarly long body and ears. In this
country, and generally in Central Europe, though the ass is by no means
uniform in appearance, it has not given rise to distinct breeds like those
of the horse. This may probably be accounted for by the animal being kept
chiefly by poor persons, who do not rear large numbers, nor carefully match
and select the young. For, as we shall see in a future chapter, the ass can
with ease be greatly improved in size and strength by careful selection,
combined no doubt with good food; and we may infer that all its other
characters would be equally amenable to selection. The small size of the
ass in England and Northern Europe is apparently due far more to want of
care in breeding than to cold; for in Western India, where the ass is used
as a beast of burden by some of the lower castes, it is not much larger
than a Newfoundland dog, "being generally not more than from twenty to
thirty inches high."[140]
The ass varies greatly in colour; and its legs, especially the fore-legs,
both in England and other countries--for instance, in China--are
occasionally barred transversely more plainly than those of dun-coloured
horses. With the horse the occasional appearance of leg-stripes was
accounted for, through the principle of reversion, by the supposition that
the primitive horse was {63} thus striped; with the ass we may confidently
advance this explanation, for the parent-form, the _A. taeniopus_, is known
to be barred, though only in a slight degree, across the legs. The stripes
are believed to occur most frequently and to be plainest on the legs of the
domestic ass during early youth,[141] as is apparently likewise the case
with the horse. The shoulder-stripe, which is so eminently characteristic
of the species, is nevertheless variable in breadth, length, and manner of
termination. I have measured a shoulder-stripe four times as broad as
another; and some more than twice as long as others. In one light-grey ass
the shoulder-stripe was only six inches in length, and as thin as a piece
of string; and in another animal of the same colour there was only a dusky
shade representing a stripe. I have heard of three white asses, not
albinoes, with no trace of shoulder or spinal stripes;[142] and I have seen
nine other asses with no shoulder-stripe, and some of them had no spinal
stripe. Three of the nine were light-greys, one a dark-grey, another grey
passing into reddish-roan, and the others were brown, two being tinted on
parts of their bodies with a reddish or bay shade. Hence we may conclude
that, if grey and reddish-brown asses had been steadily selected and bred
from, the shoulder-stripe would have been almost as generally and as
completely lost as in the case of the horse.
The shoulder-stripe on the ass is sometimes double, and Mr. Blyth has seen
even three or four parallel stripes.[143] I have observed in ten cases
shoulder-stripes abruptly truncated at the lower end, with the anterior
angle produced into a tapering point, precisely as has been figured in the
dun Devonshire pony. I have seen three cases of the terminal portion
abruptly and angularly bent; and two cases of a distinct though slight
forking. In Syria, Dr. Hooker and his party observed for me no less than
five instances of the shoulder-stripe being plainly forked over the fore
leg. In the common mule it is likewise sometimes forked. When I first
noticed the forking and angular bending of the shoulder-stripe, I had seen
enough of the stripes {64} in the various equine species to feel convinced
that even a character so unimportant as this had a distinct meaning, and
was thus led to attend to the subject. I now find that in the _Asinus
Burchellii_ and _quagga_, the stripe which corresponds with the
shoulder-stripe of the ass, as well as some of the stripes on the neck,
bifurcate, and that some of those near the shoulder have their extremities
angularly bent backwards. The forking and angular bending of the stripes on
the shoulders apparently stand in relation with the changed direction of
the nearly upright stripes on the sides of the body and neck to the
transverse bars on the legs. Finally we see that the presence of shoulder,
leg, and spinal stripes in the horse,--their occasional absence in the
ass,--the occurrence of double and triple shoulder-stripes in both animals,
and the similar manner in which these stripes terminate at their lower
extremities,--are all cases of analogous variation in the horse and ass.
These cases are probably not due to similar conditions acting on similar
constitutions, but to a partial reversion in colour to the common
progenitor of these two species, as well as of the other species of the
genus. We shall hereafter have to return to this subject, and discuss it
more fully.
* * * * *
{65}
CHAPTER III.
PIGS--CATTLE--SHEEP--GOATS.
PIGS BELONG TO TWO DISTINCT TYPES, SUS SCROFA AND
INDICA--TORF-SCHWEIN--JAPAN PIG--FERTILITY OF CROSSED PIGS--CHANGES IN
THE SKULL OF THE HIGHLY CULTIVATED RACES--CONVERGENCE OF
CHARACTER--GESTATION--SOLID-HOOFED SWINE--CURIOUS APPENDAGES TO THE
JAWS--DECREASE IN SIZE OF THE TUSKS--YOUNG PIGS LONGITUDINALLY
STRIPED--FERAL PIGS--CROSSED BREEDS.
CATTLE.--ZEBU A DISTINCT SPECIES--EUROPEAN CATTLE PROBABLY DESCENDED
FROM THREE WILD FORMS--ALL THE RACES NOW FERTILE TOGETHER--BRITISH PARK
CATTLE--ON THE COLOUR OF THE ABORIGINAL SPECIES--CONSTITUTIONAL
DIFFERENCES--SOUTH AFRICAN RACES--SOUTH AMERICAN RACES--NIATA
CATTLE--ORIGIN OF THE VARIOUS RACES OF CATTLE.
SHEEP.--REMARKABLE RACES OF--VARIATIONS ATTACHED TO THE MALE
SEX--ADAPTATIONS TO VARIOUS CONDITIONS--GESTATION OF--CHANGES IN THE
WOOL--SEMI-MONSTROUS BREEDS.
GOATS.--REMARKABLE VARIATIONS OF.
The breeds of the pig have recently been more closely studied, though much
still remains to be done, than those of almost any other domesticated
animal. This has been effected by Hermann von Nathusius in two admirable
works, especially in the later one on the Skulls of the several races, and
by Ruetimeyer in his celebrated Fauna of the ancient Swiss
lake-dwellings.[144] Nathusius has shown that all the known breeds may be
divided in two great groups: one resembling in all important respects and
no doubt descended from the common wild boar; so that this may be called
the _Sus scrofa_ group. The other group differs in several important and
constant osteological characters; its wild parent-form is unknown; the name
given to it by Nathusius, according to the law of priority, is _Sus Indica_
of Pallas. This name must now be followed, though an unfortunate one, as
the wild aboriginal does not inhabit India, and the best-known domesticated
breeds have been imported from Siam and China.
{66}
Firstly, the _Sus scrofa_ breeds, or those resembling the common wild boar.
These still exist, according to Nathusius (Schweineschaedel, s. 75), in
various parts of central and northern Europe; formerly every kingdom,[145]
and almost every province in Britain, possessed its own native breed; but
these are now everywhere rapidly disappearing, being replaced by improved
breeds crossed with the _S. Indica_ form. The skull in the breeds of the
_S. scrofa_ type resembles, in all important respects, that of the European
wild boar; but it has become (Schweineschaedel, s. 63-68) higher and broader
relatively to its length; and the hinder part is more upright. The
differences, however, are all variable in degree. The breeds which thus
resemble _S. scrofa_ in their essential skull-characters differ
conspicuously from each other in other respects, as in the length of the
ears and legs, curvature of the ribs, colour, hairiness, size and
proportions of the body.
The wild _Sus scrofa_ has a wide range, namely, Europe, North Africa, as
identified by osteological characters by Ruetimeyer, and Hindostan, as
similarly identified by Nathusius. But the wild boars inhabiting these
several countries differ so much from each other in external characters,
that they have been ranked by some naturalists as specifically distinct.
Even within Hindostan these animals, according to Mr. Blyth, form very
distinct races in the different districts; in the N. Western provinces, as
I am informed by the Rev. R. Everest, the boar never exceeds 36 inches in
height, whilst in Bengal one has been measured 44 inches in height. In
Europe, Northern Africa, and Hindostan, domestic pigs have been known to
cross with the wild native species;[146] and in Hindostan an accurate
observer,[147] Sir Walter Elliot, after describing the differences between
wild Indian and wild German boars, remarks that "the same differences are
perceptible in the domesticated {67} individuals of the two countries." We
may therefore conclude that the breeds of the _Sus scrofa_ type have either
descended from, or been modified by crossing with, forms which may be
ranked as geographical races, but which are, according to some naturalists,
distinct species.
Pigs of the _Sus Indica_ type are best known to Englishmen under the form
of the Chinese breed. The skull of _S. Indica_, as described by Nathusius,
differs from that of _S. scrofa_ in several minor respects, as in its
greater breadth and in some details in the teeth; but chiefly in the
shortness of the lachrymal bones, in the greater width of the fore part of
the palate-bones, and in the divergence of the premolar teeth. It deserves
especial notice that these latter characters are not gained, even in the
least degree, by the domesticated forms of _S. scrofa_. After reading the
remarks and descriptions given by Nathusius, it seems to me to be merely
playing with words to doubt whether _S. Indica_ ought to be ranked as a
species; for the above-specified differences are more strongly marked than
any that can be pointed out between, for instance, the fox and the wolf, or
the ass and the horse. As already stated, _S. Indica_ is not known in a
wild state; but its domesticated forms, according to Nathusius, come near
to _S. vittatus_ of Java and some allied species. A pig found wild in the
Aru islands (Schweineschaedel, s. 169) is apparently identical with _S.
Indica_; but it is doubtful whether this is a truly native animal. The
domesticated breeds of China, Cochin-China, and Siam belong to this type.
The Roman or Neapolitan breed, the Andalusian, the Hungarian, and the
"Krause" swine of Nathusius, inhabiting south-eastern Europe and Turkey,
and having fine curly hair, and the small Swiss "Buendtnerschwein" of
Ruetimeyer, all agree in their more important skull characters with _S.
Indica_, and, as is supposed, have all been largely crossed with this form.
Pigs of this type have existed during a long period on the shores of the
Mediterranean, for a figure (Schweineschaedel, s. 142) closely resembling
the existing Neapolitan pig has been found in the buried city of
Herculaneum.
Ruetimeyer has made the remarkable discovery that there lived
contemporaneously in Switzerland, during the later Stone or Neolithic
period, two domesticated forms, the _S. scrofa_, and {68} the _S. scrofa
palustris_ or Torfschwein. Ruetimeyer perceived that the latter approached
the Eastern breeds, and, according to Nathusius, it certainly belongs to
the _S. Indica_ group; but Ruetimeyer has subsequently shown that it differs
in some well-marked characters. This author was formerly convinced that his
Torfschwein existed as a wild animal during the first part of the Stone
period, and was domesticated during a later part of the same period.[148]
Nathusius, whilst he fully admits the curious fact first observed by
Ruetimeyer, that the bones of domesticated and wild animals can be
distinguished by their different aspect, yet, from special difficulties in
the case of the bones of the pig (Schweineschaedel, s. 147), is not
convinced of the truth of this conclusion; and Ruetimeyer himself seems now
to feel some doubt. As the Torfschwein was domesticated at so early a
period, and as its remains have been found in several parts of Europe,
belonging to various historic and prehistoric ages,[149] and as closely
allied forms still exist in Hungary and on the shores of the Mediterranean,
one is led to suspect that the wild _S. Indica_ formerly ranged from Europe
to China, in the same manner as _S. scrofa_ now ranges from Europe to
Hindostan. Or, as Ruetimeyer apparently suspects, a third allied species may
formerly have lived in Europe and Eastern Asia.
Several breeds, differing in the proportions of the body, in the length of
the ears, in the nature of the hair, in colour, &c., come under the _S.
Indica_ type. Nor is this surprising, considering how ancient the
domestication of this form has been both in Europe and in China. In this
latter country the date is believed by an eminent Chinese scholar[150] to
go back at least 4900 years from the present time. This same scholar
alludes to the existence of many local varieties of the pig in China; and
at the present time the Chinese take extraordinary pains in feeding and
tending their pigs, not even allowing them to walk from place to
place.[151] Hence the Chinese breed, as Nathusius has remarked,[152]
displays in an eminent degree the characters of a highly-cultivated race,
and hence, no doubt, its {69} high value in the improvement of our European
breeds. Nathusius makes a remarkable statement (Schweineschaedel, s. 138),
that the infusion of the 1/32nd, or even of the 1/64th, part of the blood
of _S. Indica_ into a breed of _S. scrofa_, is sufficient plainly to modify
the skull of the latter species. This singular fact may perhaps be
accounted for by several of the chief distinctive characters of _S.
Indica_, such as the shortness of the lachrymal bones, &c., being common to
several of the species of the genus; for in crosses the characters which
are common to many species apparently tend to be prepotent over those
appertaining to only a few species.
The Japan pig (_S. pliciceps_ of Gray), which has been recently exhibited
in the Zoological Gardens, has an extraordinary appearance from its short
head, broad forehead and nose, great fleshy ears, and deeply furrowed skin.
The following woodcut is copied from that given by Mr. Bartlett.[153] Not
only {70} is the face furrowed, but thick folds of skin, which are harder
than the other parts, almost like the plates on the Indian rhinoceros, hang
about the shoulders and rump. It is coloured black, with white feet, and
breeds true. That it has long been domesticated there can be little doubt;
and this might have been inferred even from the fact that its young are not
longitudinally striped; for this is a character common to all the species
included within the genus _Sus_ and the allied genera whilst in their
natural state.[154] Dr. Gray[155] has described the skull of this animal,
which he ranks not only as a distinct species, but places it in a distinct
section of the genus. Nathusius, however, after his careful study of the
whole group, states positively (Schweineschaedel, s. 153-158) that the skull
in all essential characters closely resembles that of the short-eared
Chinese breed of the _S. Indica_ type. Hence Nathusius considers the Japan
pig as only a domesticated variety of _S. Indica_: if this really be the
case, it is a wonderful instance of the amount of modification which can be
effected under domestication.
[Illustration: Fig. 2.--Head of Japan or Masked Pig. (Copied from Mr.
Bartlett's paper in Proc. Zoolog. Soc. 1861, p. 263.)]
Formerly there existed in the central islands of the Pacific Ocean a
singular breed of pigs. These are described by the Rev. D. Tyerman and G.
Bennett[156] as of small size, hump-backed, with a disproportionately long
head, with short ears turned backwards, with a bushy tail not more than two
inches in length, placed as if it grew from the back. Within half a century
after the introduction into these islands of European and Chinese pigs, the
native breed, according to the above authors, became almost completely lost
by being repeatedly crossed with them. Secluded islands, as might have been
expected, seem favourable for the production or retention of peculiar
breeds; thus, in the Orkney Islands, the hogs have been described as very
small, with erect and sharp ears, and "with an appearance altogether
different from the hogs brought from the south."[157]
Seeing how different the Chinese pigs, belonging to the _Sus Indica_ type,
are in their osteological characters and in external {71} appearance from
the pigs of the _S. scrofa_ type, so that they must be considered
specifically distinct, it is a fact well deserving attention, that Chinese
and common pigs have been repeatedly crossed in various manners, with
unimpaired fertility. One great breeder who had used pure Chinese pigs
assured me that the fertility of the half-breeds _inter se_ and of their
recrossed progeny was actually increased; and this is the general belief of
agriculturists. Again, the Japan pig or _S. pliciceps_ of Gray is so
distinct in appearance from all common pigs, that it stretches one's belief
to the utmost to admit that it is simply a domestic variety; yet this breed
has been found perfectly fertile with the Berkshire breed; and Mr. Eyton
informs me that he paired a half-bred brother and sister and found them
quite fertile together.
The modifications of the skull in the most highly cultivated races are
wonderful. To appreciate the amount of change, Nathusius' work, with its
excellent figures, should be studied. The whole of the exterior of the
skull in all its parts has been altered; the hinder surface, instead of
sloping backwards, is directed forwards, entailing many changes in other
parts; the front of the head is deeply concave; the orbits have a different
shape; the auditory meatus has a different direction and shape; the
incisors of the upper and lower jaws do not touch each other, and they
stand in both jaws above the plane of the molars; the canines of the upper
jaw stand in front of those of the lower jaw, and this is a remarkable
anomaly: the articular surfaces of the occipital condyles are so greatly
changed in shape, that, as Nathusius remarks (s. 133), no naturalist,
seeing this important part of the skull by itself, would suppose that it
belonged to the genus Sus. These and various other modifications, as
Nathusius observes, can hardly be considered as monstrosities, for they are
not injurious, and are strictly inherited. The whole head is much
shortened; thus, whilst in common breeds its length to that of the body is
as 1 to 6, in the "cultur-races" the proportion is as 1 to 9, and even
recently as 1 to 11.[158] The following woodcut[159] {72} of the head of a
wild boar and of a sow from a photograph of the Yorkshire Large Breed, may
aid in showing how greatly the head in a highly cultivated race has been
modified and shortened.
[Illustration: Fig. 3.--Head of Wild Boar, and of "Golden Days," a pig of
the Yorkshire Large Breed; the latter from a photograph. (Copied from
Sidney's edit. of 'The Pig,' by Youatt.)]
Nathusius has well discussed the causes of the remarkable changes in the
skull and shape of the body which the highly cultivated races have
undergone. These modifications occur chiefly in the pure and crossed races
of the _S. Indica_ type; but their commencement may be clearly detected in
the slightly improved breeds of the _S. scrofa_ type.[160] Nathusius states
positively (s. 99, 103), as the result of common experience and of his
experiments, that rich and abundant food, given during youth, tends by some
direct action to make the head broader and shorter; and that poor food
works a contrary result. He lays much stress on the fact that all wild and
semi-domesticated pigs, in ploughing up the ground with their muzzles,
have; whilst young, to exert the powerful muscles fixed to the hinder part
of the head. In highly cultivated races this habit is no longer followed,
and consequently the back of the skull becomes modified in shape, entailing
other changes in other parts. There can hardly be a doubt that so great a
change in habits would {73} affect the skull; but it seems rather doubtful
how far this will account for the greatly reduced length of the skull and
for its concave front. It is well known (Nathusius himself advancing many
cases, s. 104) that there is a strong tendency in many domestic animals--in
bull- and pug-dogs, in the niata cattle, in sheep, in Polish fowls,
short-faced tumbler pigeons, and in one variety of the carp--for the bones
of the face to become greatly shortened. In the case of the dog, as H.
Mueller has shown, this seems caused by an abnormal state of the primordial
cartilage. We may, however, readily admit that abundant and rich food
supplied during many generations would give an inherited tendency to
increased size of body, and that, from disuse, the limbs would become finer
and shorter.[161] We shall in a future chapter also see that the skull and
limbs are apparently in some manner correlated, so that any change in the
one tends to affect the other.
Nathusius has remarked, and the observation is an interesting one, that the
peculiar form of the skull and body in the most highly cultivated races is
not characteristic of any one race, but is common to all when improved up
to the same standard. Thus the large-bodied, long-eared, English breeds
with a convex back, and the small-bodied, short-eared, Chinese breeds with
a concave back, when bred to the same state of perfection, nearly resemble
each other in the form of the head and body. This result, it appears, is
partly due to similar causes of change acting on the several races, and
partly to man breeding the pig for one sole purpose, namely, for the
greatest amount of flesh and fat; so that selection has always tended
towards one and the same end. With most domestic animals the result of
selection has been divergence of character, here it has been
convergence.[162]
The nature of the food supplied during many generations has apparently
affected the length of the intestines; for, according to Cuvier,[163] their
length to that of the body in the wild boar is as 9 to 1,--in the common
domestic boar as 13.5 to 1,--and in the Siam breed as 16 to 1. In this
latter breed the greater {74} length may be due either to descent from a
distinct species or to more ancient domestication. The number of mammae
vary, as does the period of gestation. The latest authority says[164] that
"the period averages from 17 to 20 weeks," but I think there must be some
error in this statement: in M. Tessier's observations on 25 sows it varied
from 109 to 123 days. The Rev. W. D. Fox has given me ten carefully
recorded cases with well-bred pigs, in which the period varied from 101 to
116 days. According to Nathusius the period is shortest in the races which
come early to maturity; but in these latter the course of development does
not appear to be actually shortened, for the young animal is born, judging
from the state of the skull, less fully developed, or in a more embryonic
condition,[165] than in the case of common swine, which arrive at maturity
at a later age. In the highly cultivated and early matured races, the
teeth, also, are developed earlier.
The difference in the number of the vertebrae and ribs in different kinds of
pigs, as observed by Mr. Eyton,[166] and as given in the following table,
has often been quoted. The African sow probably belongs to the _S. scrofa_
type; and Mr. Eyton informs me that, since the publication of his paper,
cross-bred animals from the African and English races were found by Lord
Hill to be perfectly fertile.
----------------+--------+---------+---------+-------------+-----------
| English| | | | French
| Long- | | | | Domestic
| legged | African | Chinese | Wild Boar, | Boar, from
| Male. | Female. | Male. | from Cuvier.| Cuvier.
----------------+--------+---------+---------+-------------+-----------
Dorsal | | | | |
vertebrae | 15 | 13 | 15 | 14 | 14
| | | | |
Lumbar | 6 | 6 | 4 | 5 | 5
+--------+---------+---------+-------------+-----------
Dorsal and | | | | |
lumbar together | 21 | 19 | 19 | 19 | 19
| | | | |
Sacral | 5 | 5 | 4 | 4 | 4
+--------+---------+---------+-------------+-----------
Total number | | | | |
of vertebrae | 26 | 24 | 23 | 23 | 23
----------------+--------+---------+---------+-------------+-----------
{75}
Some semi-monstrous breeds deserve notice. From the time of Aristotle to
the present time solid-hoofed swine have occasionally been observed in
various parts of the world. Although this peculiarity is strongly
inherited, it is hardly probable that all the animals with solid hoofs have
descended from the same parents; it is more probable that the same
peculiarity has reappeared at various times and places. Dr. Struthers has
lately described and figured[167] the structure of the feet; in both front
and hind feet the distal phalanges of the two greater toes are represented
by a single, great, hoof-bearing phalanx; and in the front feet, the middle
phalanges are represented by a bone which is single towards the lower end,
but bears two separate articulations towards the upper end. From other
accounts it appears that an intermediate toe is likewise sometimes
superadded.
[Illustration: Fig. 4.--Old Irish Pig, with jaw-appendages. (Copied from H.
D. Richardson on Pigs.)]
Another curious anomaly is offered by the appendages, described by M.
Eudes-Deslongchamps as often characterizing the Normandy pigs. These
appendages are always attached to the same spot, to the corners of the jaw;
they are cylindrical, about three inches in length, covered with bristles,
and with a pencil of bristles rising out of a sinus on one side: they have
a cartilaginous centre, with two small longitudinal muscles; they occur
either symmetrically on both sides of the face or on one {76} side alone.
Richardson figures them on the gaunt old "Irish Greyhound pig;" and
Nathusius states that they occasionally appear in all the long-eared races,
but are not strictly inherited, for they occur or fail in animals of the
same litter.[168] As no wild pigs are known to have analogous appendages,
we have at present no reason to suppose that their appearance is due to
reversion; and if this be so, we are forced to admit that somewhat complex,
though apparently useless, structures may be suddenly developed without the
aid of selection. This case perhaps throws some little light on the manner
of appearance of the hideous fleshy protuberances, though of an essentially
different nature from the above-described appendages, on the cheeks of the
wart-hog or Phacochoerus Africanus.
It is a remarkable fact that the boars of all domesticated breeds have much
shorter tusks than wild boars. Many facts show that with all animals the
state of the hair is much affected by exposure to, or protection from,
climate; and as we see that the state of the hair and teeth are correlated
in Turkish dogs (other analogous facts will be hereafter given), may we not
venture to surmise that the reduction of the tusks in the domestic boar is
related to his coat of bristles being diminished from living under shelter?
On the other hand, as we shall immediately see, the tusks and bristles
reappear with feral boars, which are no longer protected from the weather.
It is not surprising that the tusks should be more affected than the other
teeth; as parts developed to serve as secondary sexual characters are
always liable to much variation.
It is a well-known fact that the young of wild European and Indian
pigs,[169] for the first six months, are longitudinally banded with
light-coloured stripes. This character generally disappears under
domestication. The Turkish domestic pigs, however, have striped young, as
have those of Westphalia, "whatever may be their hue;"[170] whether these
latter pigs belong to the {77} same curly-haired race with the Turkish
swine, I do not know. The pigs which have run wild in Jamaica and the
semi-feral pigs of New Granada, both those which are black and those which
are black with a white band across the stomach, often extending over the
back, have resumed this aboriginal character and produce
longitudinally-striped young. This is likewise the case, at least
occasionally, with the neglected pigs in the Zambesi settlement on the
coast of Africa.[171]
The common belief that all domesticated animals, when they run wild, revert
completely to the character of their parent-stock, is chiefly founded, as
far as I can discover, on feral pigs. But even in this case the belief is
not grounded on sufficient evidence; for the two main types of _S. scrofa_
and _Indica_ have never been distinguished in a feral state. The young, as
we have just seen, reacquire their longitudinal stripes, and the boars
invariably reassume their tusks. They revert also in the general shape of
their bodies, and in the length of their legs and muzzles, to the state of
the wild animal, as might have been expected from the amount of exercise
which they are compelled to take in search of food. In Jamaica the feral
pigs do not acquire the full size of the European wild boar, "never
attaining a greater height than 20 inches at the shoulder." In various
countries they reassume their original bristly covering, but in different
{78} degrees, dependent on the climate; thus, according to Roulin, the
semi-feral pigs in the hot valleys of New Granada are very scantily
clothed; whereas, on the Paramos, at the height of 7000 to 8000 feet, they
acquire a thick covering of wool lying under the bristles, like that on the
truly wild pigs of France. These pigs on the Paramos are small and stunted.
The wild boar of India is said to have the bristles at the end of its tail
arranged like the plumes of an arrow, whilst the European boar has a simple
tuft; and it is a curious fact that many, but not all, of the feral pigs in
Jamaica, derived from a Spanish stock, have a plumed tail.[172] With
respect to colour, feral pigs generally revert to that of the wild boar;
but in certain parts of S. America, as we have seen, some of the semi-feral
pigs have a curious white band across their stomachs; and in certain other
hot places the pigs are red, and this colour has likewise occasionally been
observed in the feral pigs of Jamaica. From these several facts we see that
with pigs when feral there is a strong tendency to revert to the wild type;
but that this tendency is largely governed by the nature of the climate,
amount of exercise, and other causes of change to which they have been
subjected.
The last point worth notice is that we have unusually good evidence of
breeds of pigs now keeping perfectly true, which have been formed by the
crossing of several distinct breeds. The Improved Essex pigs, for instance,
breed very true; but there is no doubt that they largely owe their present
excellent qualities to crosses originally made by Lord Western with the
Neapolitan race, and to subsequent crosses with the Berkshire breed (this
also having been improved by Neapolitan crosses), and likewise, probably,
with the Sussex breed.[173] In breeds thus formed by complex crosses, the
most careful and unremitting selection during many generations has been
found to be indispensable. Chiefly in consequence of so much crossing, some
well-known breeds have undergone rapid changes; thus, according to
Nathusius,[174] the Berkshire breed of 1780 is quite {79} different from
that of 1810; and, since this latter period, at least two distinct forms
have borne the same name.
CATTLE.
Domestic cattle are almost certainly the descendants of more than one wild
form, in the same manner as has been shown to be the case with our dogs and
pigs. Naturalists have generally made two main divisions of cattle: the
humped kinds inhabiting tropical countries, called in India Zebus, to which
the specific name of _Bos Indicus_ has been given; and the common
non-humped cattle, generally included under the name of _Bos taurus._ The
humped cattle were domesticated, as may be seen on the Egyptian monuments,
at least as early as the twelfth dynasty, that is 2100 B.C. They differ
from common cattle in various osteological characters, even in a greater
degree, according to Ruetimeyer,[175] than do the fossil species of Europe,
namely _Bos primigenius, longifrons_, and _frontosus_, from each other.
They differ, also, as Mr. Blyth,[176] who has particularly attended to this
subject, remarks, in general configuration, in the shape of their ears, in
the point where the dewlap commences, in the typical curvature of their
horns, in their manner of carrying their heads when at rest, in their
ordinary variations of colour, especially in the frequent presence of
"nilgau-like markings on their feet," and "in the one being born with teeth
protruding through the jaws, and the other not so." They have different
habits, and their voice is entirely different. The humped cattle in India
"seldom seek shade, and never go into the water and there stand knee-deep,
like the cattle of Europe." They have run wild in parts of Oude and
Rohilcund, and can maintain themselves in a region infested by tigers. They
have given rise to many races differing greatly in size, in the presence
{80} of one or two humps, in length of horns, and other respects. Mr. Blyth
sums up emphatically that the humped and humpless cattle must be considered
as distinct species. When we consider the number of points in external
structure and habits, independently of their important osteological
differences, in which they differ from each other; and that many of these
points are not likely to have been affected by domestication, there can
hardly be a doubt, notwithstanding the adverse opinion of some naturalists,
that the humped and non-humped cattle must be ranked as specifically
distinct.
The European breeds of humpless cattle are numerous. Professor Low
enumerates 19 British breeds, only a few of which are identical with those
on the Continent. Even the small Channel islands of Guernsey, Jersey, and
Alderney, possess their own sub-breeds;[177] and these again differ from
the cattle of the other British islands, such as Anglesea, and the western
isles of Scotland. Desmarest, who paid attention to the subject, describes
15 French races, excluding sub-varieties and those imported from other
countries. In other parts of Europe there are several distinct races, such
as the pale-coloured Hungarian cattle, with their light and free step, and
their enormous horns sometimes measuring above five feet from tip to
tip:[178] the Podolian cattle are remarkable from the height of their
fore-quarters. In the most recent work on Cattle,[179] engravings are given
of fifty-five European breeds; it is, however, probable that several of
these differ very little from each other, or are merely synonyms. It must
not be supposed that numerous breeds of cattle exist only in long-civilized
countries, for we shall presently see that several kinds are kept by the
savages of Southern Africa.
With respect to the parentage of the several European breeds, we
already know much from Nilsson's Memoir,[180] and more especially from
Ruetimeyer's 'Pfahlbauten' and succeeding works. Two or three species or
forms of {81} Bos, closely allied to still living domestic races, have
been found fossil in the more recent tertiary deposits of Europe.
Following Ruetimeyer, we have:--
_Bos primigenius._--This magnificent, well-known species was
domesticated in Switzerland during the Neolithic period; even at this
early period it varied a little, having apparently been crossed with
other races. Some of the larger races on the Continent, as the
Friesland, &c., and the Pembroke race in England, closely resemble in
essential structure _B. primigenius_, and no doubt are its descendants.
This is likewise the opinion of Nilsson. _Bos primigenius_ existed as a
wild animal in Caesar's time, and is now semi-wild, though much
degenerated in size, in the park of Chillingham; for I am informed by
Professor Ruetimeyer, to whom Lord Tankerville sent a skull, that the
Chillingham cattle are less altered from the true primigenius type than
any other known breed.[181]
_Bos trochoceros._--This form is not included in the three species
above mentioned, for it is now considered by Ruetimeyer to be the female
of an early domesticated form of _B. primigenius_, and as the
progenitor of his _frontosus_ race. I may add that specific names have
been given to four other fossil oxen, now believed to be identical with
_B. primigenius_.[182]
_Bos longifrons_ (or _brachyceros_) of Owen.--This very distinct
species was of small size, and had a short body with fine legs. It has
been found in England associated with the remains of the elephant and
rhinoceros.[183] It was the commonest form in a domesticated condition
in Switzerland during the earliest part of the Neolithic period. It was
domesticated in England during the Roman period, and supplied food to
the Roman legionaries.[184] Some remains have been found in Ireland in
certain crannoges, of which the dates are believed to be from 843-933
A.D.[185] Professor Owen[186] thinks it probable that the Welsh and
Highland cattle are descended from this form; as likewise is the case,
according to Ruetimeyer, with some of the existing Swiss breeds. These
latter are of different shades of colour from light-grey to
blackish-brown, with a lighter stripe along the spine, but they have no
pure white marks. The cattle of North Wales and the Highlands, on the
other hand, are generally black or dark-coloured.
_Bos frontosus_ of Nilsson.--This species is allied to _B. longifrons_,
but in the opinion of some good judges is distinct from it. Both
co-existed in Scania during the same late geological period,[187] and
both have been found in the Irish crannoges.[188] Nilsson believes that
his _B. frontosus_ may be the {82} parent of the mountain cattle of
Norway, which have a high protuberance on the skull between the base of
the horns. As Professor Owen believes that the Scotch Highland cattle
are descended from his _B. longifrons_, it is worth notice that a
capable judge[189] has remarked that he saw no cattle in Norway like
the Highland breed, but that they more nearly resembled the Devonshire
breed.
Hence we see that three forms or species of Bos, originally inhabitants of
Europe, have been domesticated; but there is no improbability in this fact,
for the genus Bos readily yields to domestication. Besides these three
species and the zebu, the yak, the gayal, and the arni[190] (not to mention
the buffalo or genus Bubalus) have been domesticated; making altogether
seven species of Bos. The zebu and the three European species are now
extinct in a wild state, for the cattle of the _B. primigenius_ type in the
British parks can hardly be considered as truly wild. Although certain
races of cattle, domesticated at a very ancient period in Europe, are the
descendants of the three above-named fossil species, yet it does not follow
that they were here first domesticated. Those who place much reliance on
philology argue that our cattle were imported from the East.[191] But as
races of men invading any country would probably give their own names to
the breeds of cattle which they might there find domesticated, the argument
seems inconclusive. There is indirect evidence that our cattle are the
descendants of species which originally inhabited a temperate or cold
climate, but not a land long covered with snow; for our cattle, as we have
seen in the chapter on Horses, apparently have not the instinct of scraping
away the snow to get at the herbage beneath. No one could behold the
magnificent wild bulls on the bleak Falkland Islands in the southern
hemisphere, and doubt about the climate being admirably suited to them.
Azara has remarked that in the temperate regions of La Plata the cows
conceive when two years old, whilst in the much hotter country of Paraguay
they do not conceive till three years old; "from which fact," as he adds,
"one may conclude that cattle do not succeed so well in warm
countries."[192]
The above-named three fossil forms of Bos have been ranked {83} by nearly
all palaeontologists as distinct species; and it would not be reasonable to
change their denomination simply because they are now found to be the
parents of several domesticated races. But what is of most importance for
us, as showing that they deserve to be ranked as species, is that they
co-existed in different parts of Europe during the same period, and yet
kept distinct. Their domesticated descendants, on the other hand, if not
separated, cross with the utmost freedom and become commingled. The several
European breeds have so often been crossed, both intentionally and
unintentionally, that, if any sterility ensued from such unions, it would
certainly have been detected. As zebus inhabit a distant and much hotter
region, and as they differ in so many characters from our European cattle,
I have taken pains to ascertain whether the two forms are fertile when
crossed. The late Lord Powis imported some zebus and crossed them with
common cattle in Shropshire; and I was assured by his steward that the
cross-bred animals were perfectly fertile with both parent-stocks. Mr.
Blyth informs me that in India hybrids, with various proportions of either
blood, are quite fertile; and this can hardly fail to be known, for in some
districts[193] the two species are allowed to breed freely together. Most
of the cattle which were first introduced into Tasmania were humped, so
that at one time thousands of crossed animals existed there; and Mr. B.
O'Neile Wilson, M.A., writes to me from Tasmania that he has never heard of
any sterility having been observed. He himself formerly possessed a herd of
such crossed cattle, and all were perfectly fertile; so much so, that he
cannot remember even a single cow failing to calve. These several facts
afford an important confirmation of the Pallasian doctrine that the
descendants of species which when first domesticated would if crossed
probably have been in some degree sterile, become perfectly fertile after a
long course of domestication. In a future chapter we shall see that this
doctrine throws much light on the difficult subject of Hybridism.
I have alluded to the cattle in Chillingham Park, which, according to
Ruetimeyer, have been very little changed from the _Bos primigenius_ type.
This park is so ancient that it is {84} referred to in a record of the year
1220. The cattle in their instincts and habits are truly wild. They are
white, with the inside of the ears reddish-brown, eyes rimmed with black,
muzzles brown, hoofs black, and horns white tipped with black. Within a
period of thirty-three years about a dozen calves were born with "brown and
blue spots upon the cheeks or necks; but these, together with any defective
animals, were always destroyed." According to Bewick, about the year 1770
some calves appeared with black ears; but these were also destroyed by the
keeper, and black ears have not since reappeared. The wild white cattle in
the Duke of Hamilton's park, where I have heard of the birth of a black
calf, are said by Lord Tankerville to be inferior to those at Chillingham.
The cattle kept until the year 1780 by the Duke of Queensberry, but now
extinct, had their ears, muzzle, and orbits of the eyes black. Those which
have existed from time immemorial at Chartley; closely resemble the cattle
at Chillingham, but are larger, "with some small difference in the colour
of the ears." "They frequently tend to become entirely black; and a
singular superstition prevails in the vicinity that, when a black calf is
born, some calamity impends over the noble house of Ferrers. All the black
calves are destroyed." The cattle at Burton Constable in Yorkshire, now
extinct, had ears, muzzle, and the tip of the tail black. Those at
Gisburne, also in Yorkshire, are said by Bewick to have been sometimes
without dark muzzles, with the inside alone of the ears brown; and they are
elsewhere said to have been low in stature and hornless.[194]
The several above-specified differences in the park-cattle, slight though
they be, are worth recording, as they show that animals living nearly in a
state of nature, and exposed to nearly uniform conditions, if not allowed
to roam freely and to cross with other herds, do not keep as uniform as
truly {85} wild animals. For the preservation of a uniform character, even
within the same park, a certain degree of selection--that is, the
destruction of the dark-coloured calves--is apparently necessary.
The cattle in all the parks are white; but, from the occasional appearance
of dark-coloured calves, it is extremely doubtful whether the aboriginal
_Bos primigenius_ was white. The following facts, however, show that there
is a strong, though not invariable, tendency in wild or escaped cattle,
under widely different conditions of life, to become white with coloured
ears. If the old writers Boethius and Leslie[195] can be trusted, the wild
cattle of Scotland were white and furnished with a great mane; but the
colour of their ears is not mentioned. The primaeval forest formerly
extended across the whole country from Chillingham to Hamilton, and Sir
Walter Scott used to maintain that the cattle still preserved in these two
parks, at the two extremities of the forest, were remnants of its original
inhabitants; and this view certainly seems probable. In Wales,[196] during
the tenth century, some of the cattle are described as being white with red
ears. Four hundred cattle thus coloured were sent to King John; and an
early record speaks of a hundred cattle with red ears having been demanded
as a compensation for some offence, but, if the cattle were of a dark or
black colour, one hundred and fifty were to be presented. The black cattle
of North Wales apparently belong, as we have seen, to the small
_longifrons_ type: and as the alternative was offered of either 150 dark
cattle, or 100 white cattle with red ears, we may presume that the latter
were the larger beasts, and probably belonged to the _primigenius_ type.
Youatt has remarked that at the present day, whenever cattle of the
short-horn breed are white, the extremities of their ears are more or less
tinged with red.
The cattle which have run wild on the Pampas, in Texas, and in two parts of
Africa, have become of a nearly uniform dark {86} brownish-red.[197] On the
Ladrone Islands, in the Pacific Ocean, immense herds of cattle, which were
wild in the year 1741, are described as "milk-white, except their ears,
which are generally black."[198] The Falkland Islands, situated far south,
with all the conditions of life as different as it is possible to conceive
from those of the Ladrones, offer a more interesting case. Cattle have run
wild there during eighty or ninety years; and in the southern districts the
animals are mostly white, with their feet, or whole heads, or only their
ears black; but my informant, Admiral Sulivan,[199] who long resided on
these islands, does not believe that they are ever purely white. So that in
these two archipelagos we see that the cattle tend to become white with
coloured ears. In other parts of the Falkland Islands, other colours
prevail: near Port Pleasant brown is the common tint; round Mount Usborne,
about half the animals in some of the herds were lead or mouse-coloured,
which elsewhere is an unusual tint. These latter cattle, though generally
inhabiting high land, breed about a month earlier than the other cattle;
and this circumstance would aid in keeping them distinct and in
perpetuating this peculiar colour. It is worth recalling to mind that blue
or lead-coloured marks have occasionally appeared on the white cattle of
Chillingham. So plainly different were the colours of the wild herds in
different parts of the Falkland Islands, that in hunting them, as Admiral
Sulivan informs me, white spots in one district, and dark spots in another
district, were always looked out for on the distant hills. In the
intermediate districts intermediate colours prevailed. Whatever the cause
may be, this tendency in the wild cattle of the Falkland Islands, which are
all descended from a few brought from La Plata, to break up into herds of
three different colours, is an interesting fact.
Returning to the several British breeds, the conspicuous difference in
general appearance between Short-horns, Long-horns (now rarely seen),
Herefords, Highland cattle, Alderneys, &c., must be familiar to every one.
A large part of the {87} difference, no doubt, may be due to descent from
primordially distinct species; but we may feel sure that there has been in
addition a considerable amount of variation. Even during the Neolithic
period, the domestic cattle were not actually identical with the aboriginal
species. Within recent times most of the breeds have been modified by
careful and methodical selection. How strongly the characters thus acquired
are inherited, may be inferred from the prices realised by the improved
breeds; even at the first sale of Colling's Short-horns, eleven bulls
reached an average of 214l., and lately Short-horn bulls have been sold for
a thousand guineas, and have been exported to all quarters of the world.
Some constitutional differences may be here noticed. The Short-horns arrive
at maturity far earlier than the wilder breeds, such as those of Wales or
the Highlands. This fact has been shown in an interesting manner by Mr.
Simonds,[200] who has given a table of the average period of their
dentition, which proves that there is a difference of no less than six
months in the appearance of the permanent incisors. The period of
gestation, from observations made by Tessier on 1131 cows, varies to the
extent of eighty-one days; and what is more interesting, M. Lefour affirms
"that the period of gestation is longer in the large German cattle than in
the smaller breeds."[201] With respect to the period of conception, it
seems certain that Alderney and Zetland cows often become pregnant earlier
than other breeds.[202] Lastly, as four fully-developed mammae is a generic
character in the genus Bos,[203] it is worth notice that with our domestic
cows the two rudimentary mammae often become fairly well developed and yield
milk.
As numerous breeds are generally found only in long-civilized countries, it
may be well to show that in some countries inhabited by barbarous races,
who are frequently at war with each other and therefore have little free
{88} communication, several distinct breeds of cattle now exist or formerly
existed. At the Cape of Good Hope Leguat observed, in the year 1720, three
kinds.[204] At the present day various travellers have noticed the
differences in the breeds in Southern Africa. Sir Andrew Smith several
years ago remarked to me that the cattle possessed by the different tribes
of Caffres, though living near each other under the same latitude and in
the same kind of country, yet differed, and he expressed much surprise at
the fact. Mr. Andersson has described[205] the Damara, Bechuana, and
Namaqua cattle; and he informs me in a letter that the cattle north of Lake
Ngami are likewise different, as Mr. Galton has heard is the case with the
cattle of Benguela. The Namaqua cattle in size and shape nearly resemble
European cattle, and have short stout horns and large hoofs. The Damara
cattle are very peculiar, being big-boned, with slender legs and small hard
feet; their tails are adorned with a tuft of long bushy hair nearly
touching the ground, and their horns are extraordinarily large. The
Bechuana cattle have even larger horns, and there is now a skull in London
with the two horns 8 ft. 81/4 in. long, as measured in a straight line from
tip to tip, and no less than 13ft. 5in. as measured along their curvature!
Mr. Andersson in his letter to me says that, though he will not venture to
describe the differences between the breeds belonging to the many different
sub-tribes, yet such certainly exist, as shown by the wonderful facility
with which the natives discriminate them.
That many breeds of cattle have originated through variation, independently
of descent from distinct species, we may infer from what we see in South
America, where the genus Bos was not endemic, and where the cattle which
now exist in such vast numbers are the descendants of a few imported from
Spain and Portugal. In Columbia, Roulin[206] describes two peculiar breeds,
namely, _pelones_, with extremely thin and fine hair, and _calongos_,
absolutely naked. According to Castelnau there are two races in Brazil, one
like European cattle, the other different, with {89} remarkable horns. In
Paraguay, Azara describes a breed which certainly originated in S. America,
called _chivos_, "because they have straight vertical horns, conical, and
very large at the base." He likewise describes a dwarf race in Corrientes,
with short legs and a body larger than usual. Cattle without horns, and
others with reversed hair, have also originated in Paraguay.
Another monstrous breed, called niatas or natas, of which I saw two small
herds on the northern bank of the Plata, is so remarkable as to deserve a
fuller description. This breed bears the same relation to other breeds, as
bull or pug dogs do to other dogs, or as improved pigs, according to H. von
Nathusius, do to common pigs.[207] Ruetimeyer believes that these cattle
belong to the primigenius type.[208] The forehead is very short and broad,
with the nasal end of the skull, together with the whole plane of the upper
molar-teeth, curved upwards. The lower jaw projects beyond the upper, and
has a corresponding upward curvature. It is an interesting fact that an
almost similar conformation characterizes, as I have been informed by Dr.
Falconer, the extinct and gigantic Sivatherium of India, and is not known
in any other ruminant. The upper lip is much drawn back, the nostrils are
seated high up and are widely open, the eyes project outwards, and the
horns are large. In walking the head is carried low, and the neck is short.
The hind legs appear to be longer, compared with the front legs, than is
usual. The exposed incisor teeth, the short head and upturned nostrils,
give these cattle the most ludicrous, self-confident air of defiance. The
skull which I presented to the College of Surgeons has been thus described
by Professor Owen:[209] "It is remarkable from the stunted development of
the nasals, premaxillaries, and fore-part of the lower jaw, which is
unusually {90} curved upwards to come into contact with the premaxillaries.
The nasal bones are about one-third the ordinary length, but retain almost
their normal breadth. The triangular vacuity is left between them, the
frontal and lachrymal, which latter bone articulates with the premaxillary,
and thus excludes the maxillary from any junction with the nasal." So that
even the connexion of some of the bones is changed. Other differences might
be added: thus the plane of the condyles is somewhat modified, and the
terminal edge of the premaxillaries forms an arch. In fact, on comparison
with the skull of a common ox, scarcely a single bone presents the same
exact shape, and the whole skull has a wonderfully different appearance.
The first brief published notice of this race was by Azara, between the
years 1783-96; but Don F. Muniz, of Luxan, who has kindly collected
information for me, states that about 1760 these cattle were kept as
curiosities near Buenos Ayres. Their origin is not positively known, but
they must have originated subsequently to the year 15
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