The Variation of Animals and Plants under Domestication

OM THE COMMON WILD-DUCK-DIFFERENCES IN THE DIFFERENT BREEDS-OSTE

TICATED-LITTLE VARIATI

N OF BLACK-SHO

WITH THE UNITED STATES SPE

NARY-BIRD, GOLD

N-DIFFERENCES IN THE DIFFERENT RACES-IN THE EGG, CATERPILLAR, AND COCOON STATES

first briefly describe the chi

skull perforated beneath. The top-knot in a duck which I imported from Holland was two and a half inches in diameter. (4) Labrador (or Canadian, or Buenos Ayres, or East Indian); plumage entirely black; beak broader, relatively to its length, than in the wild-duck; eggs slightly tinted with black. This sub-breed perhaps ought to be ranked as a breed; it includes two sub-varieties, one as large as the common domestic duck, which I have kept alive, and the other smaller and often capable o

n tufted. The common colour is white, but some are coloured like wild-ducks. It is an ancient breed, having been noticed in 1676.[4

m the extraordinary loquacity of the female. Beak short. Th

he Malayan archipelago. It walks with its body extremely erect, and with its thin neck stretched straig

ter. We have some historical evidence with respect to the period and progress of the domestication of the duck. It was unknown[441] to the ancient Egyptians, to the Jews of the Old Testament, and to the Greeks of the Homeric period. About eighteen centuries ago Columella[442] and Varro speak of the necessity of keeping ducks in netted enclosures like other wild fowl, so that at this period there was danger of their flying away. Moreover, the plan recommended by Columella to those who might wish to increase their stock of ducks, namely

g wild ducks die off, leaving their more hardy brethren in undisturbed possession of their foster-mother's care. The difference of habit at the onset in the newly-hatched ducklings almost entails such a result to a certainty." The wild ducklings were from the first quite tame towards those who took care of them as long as they wore the same clothes, and likewise to the dogs and cats of the house. They would even snap with their beaks at the dogs, and drive them away from any spot which they coveted. But they were much alarmed at strange men and dogs. Differently from what occurred in Sweden, Mr. Hewitt found that his young birds always changed and deteriorated in character in the course of two or three generations; notwithstanding that great care was taken to prevent any crossing with tame ducks. After the third generatio

g had abnormal characters in comparison with all the other species of the genus, as with hook-billed and penguin ducks;-on all the breeds, as far as is known, being fertile together;[445]-on all the breeds having the same general disposition, instinct, &c. But one fact bearing on this question may be noticed: in the great duck family, one species alone, namely, the male of A. boschas, has its four middle tail-feathers curled upwardly; now in every one of the above-named domestic breeds these curled feathers exist, and on the supposition th

arts of the plumage of the wild mallard. But I found this drake to be identical in every feather with a variety of the common breed procured from a farm-yard in Kent, and I have occasionally elsewhere seen similar specimens. The occurrence of a duck bred under so peculiar a climate as that of the Malayan archipelago, where the wild species does not exist, with exactly the same plumage as may occasionally be seen in our farm-yards, is a fact worth no

eathers, and from certain sub-varieties in each breed occasionally resembling in general plumage

ome degree of correlation exists between the colour of the plumage and the egg-shell. A good observer assured me that one year his Labrador ducks laid almost perfectly white eggs, but that the yolks were this same season dirty olive-green, instead of as usual of a golden yellow, so that the black tint appeared to have passed inwa

in a duck having no other peculiarity which was sent to me from the Malayan archipelago. The tuft is only so far interesting as it affects the skull, which is thus rendered slightly more globular, and is perforated by numerous apertures. Call-ducks are remarkable from their extraordinary loquacity: the drake only hisses like common drakes; nevertheless, when paired with the common duck, he transmits to his female offspring a strong quacking tendency. This loquacity seems at first a surprising character to have been acquired under domestication. But the voice varies in the different breeds; Mr. Brent[450

en tail-feathers in two Labrador ducks. On the middle toe, in three specimens, there were twenty-seven or twenty-eight scutell?, whereas in two wild ducks there were thirty-one and thirty-two. The Penguin when crossed transmits with much power its peculiar form of body and gait to its offspring; this was manifest with some hybrids raised in the Zoological Gardens between one of these birds and the Egyptian goose

duced to two-thirds of the natural si

ell as the lower jaw curve downwards in a most remarkable manner, as represented. In the Labrador duck the premaxillaries are rather broader than in the wild duck; and in two skulls of this breed the vertical ridges on each side of the supra-occipital bone are very prominent. In the Penguin the premaxillaries are relatively shorter than in the wild duck; and the inferior points of the paramastoids more prominent. In a Dutch tufted duck, the skull under the enormous tuft was slightly mor

mal surface. B. Eighth cervical vertebra of Call Duck, viewed as above. C. Twelfth cervical vertebr

attached to the fifteenth cervical vertebra, the h?mal spines of the thirteenth and fourteenth (cervical) and of the seventeenth (dorsal) vertebr? corresponded with the spines on the fourteenth, fifteenth, and eighteenth vertebr? of the wild duck: so that each of these vertebr? had acquired a structure proper to one posterior to it in position. In the twelfth cervical vertebra of this same Call-duck (fig. 40, B), the two branches of the h?mal spine stand much closer together than in the wild duck (A), and the descending h?mal processes are much shortened. In the Penguin duck the neck from its thinness and erectness falsely appears (as ascertained by measurement) to be much elongated, but the cervical and dorsal vertebr? present no difference; the posterior dorsal vertebr?, however, are more completely anchylosed to the pe

males of the Penguin, Call, Hook-billed, Labrador, and

me other breeds the ischiadic foramen is less elongated. In the sternum, furcula, coracoids, and scapula, the differences are so slight and so

s (but not the tibia) are considerably lengthened, relatively to the same bones in the wild duck, and to the wing-bones in both birds. This elongation of the leg-bones could be seen whilst the bird was alive, and

g (measured separately after having been cleaned) relatively to those of the leg have become slightly

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ut from the increased weight and length of the bones of the legs. The first of the two tables on the next page shows that the leg-bones relatively to the weight of the entire skeleton have really increased in weight; but the second table shows that according to the same standard the wing-bones have als

me proportionally heavier or lighter; but their greater weight in all the breeds relatively to the other bones can be accounted for only by these domestic birds having used their legs in walking and standing much more than the wild, for they never fly, and the more artificial breeds rarely swim. In the second table we see, with the exception of one case, a plain reduction in the weight of the bones of the wing, and this no doubt has resulted from their lessened use. The one exceptional ca

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e hundred in the former to eighty-nine in the latter; this shows that these bones in the domestic duck have been reduced eleven per cent. of their due proportional weight. The promin

tate of their organs of flight our domesticated ducks. This is the case with the water-hen (Gallinula nesiotis) of Tristan d'Acunha, which "can flutter a little, but obviously uses its legs, and not its wings, as a mode of escape." Now Mr. Sclater[454] finds in this bird that the wings, sternum, and coracoids, are all reduced in length, and the crest of the sternum in depth, in comparison with the same bones in the European water-hen (G. chloro

Go

fficulty is chiefly due to the existence of three or four closely allied wild European species[456]. A large majority of capable judges are convinced that our geese are descended from the wild Grey-lag goose (A. ferus); the young of which can easily be tamed,[457] and are domesticated by the Laplanders. This species, when crossed with the domestic goose, produced in the Zoological Gardens, as I was assured in 1849, perfectly fertile offspring.[458] Yarrell[459] has obs

ted, is perforated. A sub-breed has lately been formed with the feathers reversed at the back of the head and neck.[462] The beak varies a little in size, and is of a yellower tint than in the wild species; but its colour and that of the legs are both slightly variable.[463] This latter fact deserves attention, because the colour of the legs and beak is highly serviceable in discriminating the several closely allied wild forms.[464] At our Shows two breeds are exhibited; viz. the Embden and Toulouse; but they differ in nothing except colour.[465] Recently a smaller and singular variety has been imported from Sebastopol,[466] with the scapular feathers (as I hear from Mr. Tegetmeier, who sent me specimens) greatly elongated, curled, and even spirally twisted. The margins of these feathers are rendere

naments; no one makes a pet of the goose; the name, indeed, in more languages than one, is a term of reproach. The goose is valued for its size and flavour, for the whiteness of its feathers which adds to their value, and for its prolificness and tameness. In all these points the goose differs from the wild parent-form; and these are the points which have been sele

Peac

they were identical in every respect, except that the plumage of the latter was perhaps rather thicker. Whether our birds are descended from those introduced into Europe in the time of Alexander, or have been

ountry, but not in India, where it is certainly unknown. These japanned birds differ conspicuously from the common peacock in the colour of their secondary wing-feathers, scapulars, wing-coverts, and thighs; the females are much paler, and the young, as I hear from Mr. Bartlett, likewise differ. They can be propagat

es of japanned birds suddenly appearing in flocks of the common kind kept in England. Better evidence of the first appearance of a new variety could hardly be desired. If we reject this evidence, and believe that the japanned peacock is a distinct species, we must suppose in all these cases that the common breed had at some former period been crossed with the supposed P. nigripennis, but had lost every trace of the cross, yet that the birds occasionally produced offspring which suddenly and completely reacquired through reversion the characters of P. nigripennis. I have heard of no other such case in the animal or vegetable kingdom. To perceive the full improbability of such an occurrence, we may suppose that a breed of dogs had been crossed at some former period with a wolf, but had lost every trace of the wolf-like character, yet that the breed gave birth in five instances in the same country, within no great length of time, to a wolf perfect in ev

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because in the United States wild male turkeys sometimes court the domestic hens, which are descended from the Mexican form, "and are generally received by them with great pleasure."[471] Several accounts have likewise been published of young birds, reared in the United States from the eggs of the wild species, crossing and commingling with the common breed. In England, also, this same species has been kept in several parks; from two of which the Rev. W. D. Fox procured birds, and they crossed freely with the common domestic kind, and

chickens are generally mottled all over with brownish-grey.[473] The tuft of hair on the breast, which is proper to the male alone, occasionally appears on the breast of the domesticated female.[474] The inferior tail-coverts vary in number, and according to a German superstition the hen lays as many eggs as the cock has feathers of this kind.[475] In Holland there was formerly, according to Temminck, a beautiful buff-yellow breed, furnished with an ample white topknot. Mr. Wilmot has described[476] a white turkey-coc

e of the latter kept at Oulton by Sir P. Egerton, though precluded from crossing with common turkeys, occasionally produced much paler-coloured birds, and one that was almost white, but not an albino. These half-wild turkeys in thus slightly differing from each other present an analogous case with the wild cattle kept in the several British parks. We must suppose that the differences have resulted from the prevention of f

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s hardly varied at all, except in the plumage being either paler or darker-coloured. It is a singular fact that this bird varies more in colour in the West Indies and on the Spanish Main, under a hot though humid climate, than in Europe.[478] The guinea-fowl has become thoroughly feral in Jamaica a

anary

g a considerable period. The greater number of the varieties differ only in colour and in the markings of their plumage. Some breeds, however, differ in shape, such as the hooped or bowed canaries, and the Belgian canaries with their much elongated bodies. Mr. Brent[481] measured one of the latter and found it eight inches in length, whilst the wild canary is only five and a quarter inches long. There are topknotted canaries, and it is a singular fact, that, if two topknotted birds are matched, the young, instead of having very fine topknots, are generally bald, or even have a wound on their heads.[482] It would appear as if the topknot

d-F

t it is an almost universal law that animals, when removed from their natural conditions of life, vary, and that ra

auvigny has described and given coloured drawings of no less than eighty-nine varieties.[485] Many of the varieties, however, such as triple tail-fins, &c., ought to be called monstrosities; but it is difficult to draw any distinct line between a variation and a monstrosity. As gold-fish are kept for ornament or curiosity, and as "the Chinese are just the people to have secluded a chance variety of any kind, and to have matched and paired from it,"[486] we may feel nearly c

es double, and the tail is often triple. This latter deviation of structure seems generally to occur "at the expense of the whole or part of some other fin;"[488] but Bory de Saint Vincent[489] saw at Madrid gold-fish furnished with a dorsal fin and a triple tail. One variety is characterized by a hump on its back near the head; and the Rev. L. Jenyns[490] has described a most sin

e-B

ombs are smaller, owing to the cells having become smaller from the successive old cocoons. The best authorities[492] concur that, with the exception of the Ligurian race or species, presently to be mentioned, distinct breeds do not exist in Britain or on the Continent. There is, however, even in the same stock, some variability in colour. Thus Mr. Woodbury states[493] that he has several times seen queen bees of the common kind annulated with yellow like Ligurian queens, and the latter dark-coloured like common bees. He has also observed variations in the colour of the drones, without any corresponding difference in the queens or workers of the same hive. The great apiarian Dzierzon, in answer to my queries on this subject, says[494] that in Germany bees of some stocks are decidedly dark, whilst others are remarkable for their yellow colour. Bees also seem to differ in habits in different districts, for Dzier

m other bees would, as we now know, be indispensable; for since the introduction of the Ligurian bee into Germany and England, it has been found that the drones wander at least two miles from their own hives, and often cross with the queens of the common bee.[495] The Ligurian bee, although perfectly fertile when crossed with the common kind, is ranked by most naturalists as a distinct species, whilst by others it is ranked as a natural variety: but this form need

ity. From the date of the introduction of the Ligurian bee into Great Britain we may feel sure that these bees had not been crossed with this form. Mr. Lowe propagated this variety, but unfortunately did not separate the stock from his other bees, and after three generations the new character was almost completely

k-M

ding periods. As the value of the silk-moth depends entirely on the cocoon, every change in its structure and qualities has been carefully attended to, and races differing much in the

h the common silk-moth, as has been recently ascertained in France. Captain Hutton[498] states that throughout the world at least six species have been domesticated; and he believes that the silk-moths reared in Europe bel

e food given to the caterpillar influences to a certain extent the character of the breed.[500] Disuse has apparently aided in checking the development of the wings. But the most important element in the production of the many now existing, much modified races, no doubt has been the close attention which has long been applied in many countries to every promising variation. The care taken in Europe in the selection of the best cocoons and moths for br

wing spring; and it is in vain, says M. Robinet, to expose them to a temperature gradually raised, in order that the caterpillar may be quickly developed. Yet occasionally, without any known cause, batches of eggs are produced, which immediately begin to undergo the proper changes, and are hatched in from twenty to thirty days. From these and some other analogous facts it may be concluded that the Trevoltini silkworm

r is disregarded by cultivators, and has not been fixed by selection. Captain Hutton, in the paper before referred to, has argued with much force that the dark tiger-like marks, which so frequently appear during the later moults in the caterpillars of various breeds, are due to reversion; for the caterpillars of several allied wild species of Bombyx are marked and coloured in this manner. He separated some caterpillars with

se caterpillars, and having kept the moths separate, bred from them. Of the many caterpillars thus reared, "every one without exception had eyebrows, some darker and more decidedly marked than the others, but all had eyebrows more or less plainly visible." Black caterpillars occasionally appear amongst those of the common kind, but in so variable a manner,

nce would not have arisen under domestication; but M. Robinet[507] states that, on the one hand, ordinary caterpillars occasionally spin their cocoons after only three moults, and, on the other hand, "presque toutes les races à trois mues, que nous a

s, or with one end alone, more or less pointed. The silk varies in fineness and quality, and in being nearly white, of two tints, or yellow. Generally the colour of the silk is not strictly inherited: but in the chapter on Selection I shall give a curious account how, in the course of sixty-five generations, the number of yellow cocoons in one breed has been reduced in France from one hundred to thirty-five in the thousand. Accordin

eminent naturalist M. de Quatrefages. Captain Hutton also says[509] that the moths of all kinds vary much in colour, but in nearly the same inconstant manner. Considering how much the cocoons in the several races differ, this fac

the development of their wings, yet I was assured by Mrs. Whitby that the males of the moths bred by her used their wings more than the females, and could flutter downwards, though never upwards. She also states that, when the females first emerge from the cocoon, their wings are less expanded than those of the male. The degree of imperfection, however, in the wings varies much in different races and under different circumstances; M. Quatrefages[511] says that he has seen a number of moths with their wings reduced to a third, fourth, or tenth part of their normal dimensions, an

which they are laid,[512] but this proceeds, according to Capt. H

base of the leaf on which they are feeding, and consequently fall down; but they are capable, according to M. Robinet,[514] of again crawling up the trunk. Even this capacity sometimes

hite, whilst those which give yellow cocoons are invariably yellow.[516] We have seen that the caterpillars with dark tiger-like stripes produce moths which are more darkly shaded than other moths. It seems well established[517] that in France the caterpillars of the races which produce white silk, an

estication. We learn also the more important fact that variations may occur at various periods of life, and be in