Чарльз Дарвин
The Variation of Animals and Plants under Domestication — Volume 1
I examined the bony enlargement of the trachea in the males of the Penguin, Call, Hook-billed, Labrador, and Aylesbury breeds; and in all it was identical in shape.
The PELVIS is remarkably uniform; but in the skeleton of the Hook-billed duck the anterior part is much bowed inwards; in the Aylesbury and some other breeds the ischiadic foramen is less elongated. In the sternum, furculum, coracoids, and scapulae, the differences are so slight and so variable as not to be worth notice, except that in two skeletons of the Penguin duck the terminal portion of the scapula was much attenuated.
In the bones of the leg and wing no modification in shape could be observed. But in the Penguin and Hook-billed ducks, the terminal phalanges of the wing are a little shortened. In the former, the femur, and metatarsus (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 is no doubt connected with its peculiar upright manner of walking. In a large Aylesbury duck, on the other hand, the tibia was the only bone of the leg which relatively to the other bones was slightly lengthened.
ON THE EFFECTS OF THE INCREASED AND DECREASED USE OF THE LIMBS.
In all the breeds the bones of the wing (measured separately after having been cleaned) relatively to those of the leg have become slightly shortened, in comparison with the same bones in the wild duck, as may be seen in Table 8.I.
TABLE 8.I.a.
COLUMN 1. Length of Femur, Tibia, and Metatarsus together (inches).
COLUMN 2. Length of Humerus, Radius, and Metacarpus together (inches).
COLUMN 3. Or as (ratio).
Name of Breed. 1. 2. 3.
Wild mallard. 7.14 9.28 100:129
Aylesbury. 8.64 10.43 100:120
Tufted (Dutch). 8.25 9.83 100:119
Penguin. 7.12 8.78 100:123
Call. 6.20 7.77 100:125
TABLE 8.I.b.
COLUMN 1. Length of Femur, Tibia, and Metatarsus together (inches).
COLUMN 2. Length of all the bones of the wing (inches).
COLUMN 3. Or as (ratio).
Name of Breed. 1. 2. 3.
Wild duck (another specimen). 6.85 10.07 100:147
Common domestic duck. 8.15 11.26 100:138
In table 8.I we see, by comparison with the wild duck, that the reduction in the length of the bones of the wing, relatively to those of the legs, though slight, is universal. The reduction is least in the Call duck, which has the power and the habit of frequently flying.
In weight there is a greater relative difference between the bones of the leg and wing, as may be seen in Table 8.II:
TABLE 8.II.a.
COLUMN 1. Weight of Femur, Tibia, and Metatarsus (grains).
COLUMN 2. Weight of Humerus, Radius, and Metacarpus (grains).
COLUMN 3. Or as (ratio).
Name of Breed. 1. 2. 3.
Wild mallard. 54 97 100:179
Aylesbury. 164 204 100:124
Hooked-bill. 107 160 100:149
Tufted (Dutch). 111 148 100:133
Penguin. 75 90.5 100:120
Labrador. 141 165 100:117
Call. 57 93 100:163
TABLE 8.II.b.
COLUMN 1. Weight of all the Bones of the Leg and Foot (grains).
COLUMN 2. Weight of all the Bones of the Wing (grains).
COLUMN 3. Or as (ratio).
Name of Breed. 1. 2. 3.
Wild (another specimen). 66 115 100:173
Common domestic duck. 127 158 100:124
In these domesticated birds, the considerably lessened weight of the bones of the wing (i.e. on an average, twenty-five per cent of their proper proportional weight), as well as their slightly lessened length, relatively to the leg-bones, might follow, not from any actual decrease in the wing- bones, but from the increased weight and length of the bones of the legs.
TABLE 8.III.a.
COLUMN 1. Weight of entire Skeleton (grains). (N.B. One Metatarsus and Foot was removed from each skeleton, as it had been accidentally lost in two cases.)
COLUMN 2. Weight of Femur, Tibia, and Metatarsus (grains).
COLUMN 3. Or as (ratio).
Name of Breed. 1. 2. 3.
Wild mallard. 839 54 1000:64
Aylesbury. 1925 164 1000:85
Tufted (Dutch). 1404 111 1000:79
Penguin. 871 75 1000:86
Call (from Mr. Fox). 717 57 1000:79
TABLE 8.III.b.
COLUMN 1. Weight of entire Skeleton (grains). (N.B. One Metatarsus and Foot was removed from each skeleton, as it had been accidentally lost in two cases.)
COLUMN 2. Weight of Humerus, Radius and Metacarpus (grains).
COLUMN 3. Or as (ratio).
Name of Breed. 1. 2. 3.
Wild mallard. 839 97 1000:115
Aylesbury. 1925 204 1000:105
Tufted (Dutch). 1404 148 1000:105
Penguin. 871 90 1000:103
Call (from Mr. Baker). 914 100 1000:109
Call (from Mr. Fox). 717 92 1000:129
Table 8.III.a shows that the leg-bones relatively to the weight of the entire skeleton have really increased in weight; but Table 8.III.b shows that according to the same standard the wing-bones have also really decreased in weight; so that the relative disproportion shown in the foregoing tables between the wing and leg-bones, in comparison with those of the wild duck, is partly due to the increase in weight and length of the leg-bones, and partly to the decrease in weight and length of the wing- bones.
With respect to Tables 8.III.a and b, I may first state that I tested them by taking another skeleton of a wild duck and of a common domestic duck, and by comparing the weight of ALL the bones of the leg with ALL those of the wings, and the result was the same. In the first of these tables we see that the leg-bones in each case have increased in actual weight. It might have been expected that, with the increased or decreased weight of the entire skeleton, the leg-bones would have become 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 case, namely, in one of the Call ducks, is in truth no exception, for this bird was constantly in the habit of flying about; and I have seen it day after day rise from my grounds, and fly for a long time in circles of more than a mile in diameter. In this Call duck there is not only no decrease, but an actual increase in the weight of the wing-bones relatively to those of the wild-duck; and this probably is consequent on the remarkable lightness and thinness of all the bones of the skeleton.
Lastly, I weighed the furculum, coracoids, and scapula of a wild duck and of a common domestic duck, and I found that their weight, relatively to that of the whole skeleton, was as one 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 prominence of the crest of the sternum, relatively to its length, is also much reduced in all the domestic breeds. These changes have evidently been caused by the lessened use of the wings.]
It is well known that several birds, belonging to different Orders, and inhabiting oceanic islands, have their wings greatly reduced in size and are incapable of flight. I suggested in my 'Origin of Species' that, as these birds are not persecuted by any enemies, the reduction of their wings had probably been caused by gradual disuse. Hence, during the earlier stages of the process of reduction, such birds would probably have resembled our domesticated ducks in the state of their organs of flight. 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 (8/19. 'Proc. Zoolog. Soc.' 1861 page 261.) 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. chloropus). On the other hand, the thigh-bones and pelvis are increased in length, the former by four lines, relatively to the same bones in the common water-hen. Hence in the skeleton of this natural species nearly the same changes have occurred, only carried a little further, as with our domestic ducks, and in this latter case I presume no one will dispute that they have resulted from the lessened use of the wings and the increased use of the legs.
THE GOOSE.
This bird deserves some notice, as hardly any other anciently domesticated bird or quadruped has varied so little. That geese were anciently domesticated we know from certain verses in Homer; and from these birds having been kept (388 B.C.) in the Capitol at Rome as sacred to Juno, which sacredness implies great antiquity. (8/20. 'Ceylon' by Sir J.E. Tennent 1859 volume 1 page 485; also J. Crawfurd on the 'Relation of Domest. Animals to Civilisation' read before Brit. Assoc. 1860. See also 'Ornamental Poultry' by Rev. E.S. Dixon 1848 page 132. The goose figured on the Egyptian monuments seems to have been the Red goose of Egypt.) That the goose has varied in some degree, we may infer from naturalists not being unanimous with respect to its wild parent-form; though the difficulty is chiefly due to the existence of three or four closely allied wild European species. (8/21. Macgillivray's 'British Birds' volume 4 page 593.) A large majority of capable judges are convinced that our geese are descended from the wild Grey-leg goose (Anser ferus); the young of which can easily be tamed. (8/22. Mr. A. Strickland, 'Annals and Mag. of Nat. Hist.' 3rd series volume 3 1859 page 122, reared some young wild geese, and found them in habits and in all characters identical with the domestic goose.) This species, when crossed with the domestic goose, produced in the Zoological Gardens, as I was assured in 1849, perfectly fertile offspring. (8/23. See also Hunter 'Essays' edited by Owen volume 2 page 322.) Yarrell (8/24. Yarrell's 'British Birds' volume 3 page 142.) has observed that the lower part of the trachea of the domestic goose is sometimes flattened, and that a ring of white feathers sometimes surrounds the base of the beak. These characters seem at first sight good indications of a cross at some former period with the white-fronted goose (A. albifrons); but the white ring is variable in this latter species, and we must not overlook the law of analogous variation; that is, of one species assuming some of the characters of allied species.
As the goose has proved so little flexible in its organisation under long- continued domestication, the amount of variation which it has undergone may be worth giving. It has increased in size and in productiveness (8/25. L. Lloyd 'Scandinavian Adventures' 1854 volume 2 page 413, says that the wild goose lays from five to eight eggs, which is a much fewer number than that laid by our domestic goose.); and varies from white to a dusky colour. Several observers (8/26. The Rev. L. Jenyns (Blomefield) seems first to have made this observation in his 'British Animals.' See also Yarrell, and Dixon in his 'Ornamental Poultry' (page 139), and 'Gardener's Chronicle' 1857 page 45.) have stated that the gander is more frequently white than the goose, and that when old it almost invariably becomes white; but this is not the case with the parent-form, the A. ferus. Here, again, the law of analogous variation may have come into play, as the almost snow-white male of the Rock goose (Bernicla antarctica) standing on the sea-shore by his dusky partner is a sight well known to those who have traversed the sounds of Tierra del Fuego and the Falkland Islands. Some geese have top-knots; and the skull beneath, as before stated, is perforated. A sub-breed has lately been formed with the feathers reversed at the back of the head and neck. (8/27. Mr. Bartlet exhibited the head and neck of a bird thus characterised before the Zoological Soc. February 1860.) 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. (8/28. W. Thompson 'Natural Hist. of Ireland' 1851 volume 3 page 31. The Rev. E.S. Dixon gave me some information on the varying colour of the beak and legs.) This latter fact deserves attention, because the colour of the legs and beak is highly serviceable in discriminating the several closely allied wild forms. (8/29. Mr. A. Strickland in 'Annals and Mag. of Nat. Hist.' 3rd series volume 3 1859 page 122.) At our Shows two breeds are exhibited; viz., the Embden and Toulouse; but they differ in nothing except colour. (8/30. 'Poultry Chronicle' volume 1 1854 page 498; volume 3 page 210.) Recently a smaller and singular variety has been imported from Sebastopol (8/31. 'The Cottage Gardener' September 4, 1860 page 348.), 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 rendered plumose by the divergence of the barbs and barbules, so that they resemble in some degree those on the back of the black Australian swan. These feathers are likewise remarkable from the central shaft, which is excessively thin and transparent, being split into fine filaments, which, after running for a space free, sometimes coalesce again. It is a curious fact that these filaments are regularly clothed on each side with fine down or barbules, precisely like those on the proper barbs of the feather. This structure of the feathers is transmitted to half-bred birds. In Gallus sonneratii the barbs and barbules blend together, and form thin horny plates of the same nature with the shaft: in this variety of the goose, the shaft divides into filaments which acquire barbules, and thus resemble true barbs.
Although the domestic goose certainly differs somewhat from any known wild species, yet the amount of variation which it has undergone, as compared with that of most domesticated animals, is singularly small. This fact can be partially accounted for by selection not having come largely into play. Birds of all kinds which present many distinct races are valued as pets or ornaments; 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 selected. Even in ancient times the Roman gourmands valued the liver of the WHITE goose; and Pierre Belon (8/32. 'L'Hist. de la Nature des Oiseaux' par P. Belon 1555 page 156. With respect to the livers of white geese being preferred by the Romans see Isid. Geoffroy St. — Hilaire 'Hist. Nat. Gen.' tome 3 page 58.) in 1555 speaks of two varieties, one of which was larger, more fecund, and of a better colour than the other; and he expressly states that good managers attended to the colour of their goslings, so that they might know which to preserve and select for breeding.
THE PEACOCK.
This is another bird which has hardly varied under domestication, except in sometimes being white or piebald. Mr. Waterhouse carefully compared, as he informs me, skins of the wild Indian and domestic bird, and 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 subsequently imported, is doubtful. They do not breed very freely with us, and are seldom kept in large numbers, — circumstances which would greatly interfere with the gradual selection and formation of new breeds.
There is one strange fact with respect to the peacock, namely, the occasional appearance in England of the "japanned" or "black-shouldered" kind. This form has lately been named on the high authority of Mr. Sclater as a distinct species, viz. Pavo nigripennis, which he believes will hereafter be found wild in some country, but not in India, where it is certainly unknown. The males of these japanned birds differ conspicuously from the common peacock in the colour of their secondary wing-feathers, scapulars, wing-coverts, and thighs, and are I think more beautiful; they are rather smaller than the common sort, and are always beaten by them in their battles, as I hear from the Hon. A.S.G. Canning. The females are much paler coloured than those of the common kind. Both sexes, as Mr. Canning informs me, are white when they leave the egg, and they differ from the young of the white variety only in having a peculiar pinkish tinge on their wings. These japanned birds, though appearing suddenly in flocks of the common kind, propagate their kind quite truly. Although they do not resemble the hybrids which have been raised between P. cristatus and muticus, nevertheless they are in some respects intermediate in character between these two species; and this fact favours, as Mr. Sclater believes, the view that they form a distinct and natural species. (8/33. Mr. Sclater on the black-shouldered peacock of Latham 'Proc. Zoolog. Soc.' April 24, 1860. Mr. Swinhoe at one time believed, 'Ibis' July 1868, that this kind of peafowl was found wild in Cochin China, but he has since informed me that he feels very doubtful on this head.)
On the other hand, Sir H. Heron states (8/34. 'Proc. Zoolog. Soc.' April 14, 1835.) that this breed suddenly appeared within his memory in Lord Brownlow's large stock of pied, white, and common peacocks. The same thing occurred in Sir J. Trevelyan's flock composed entirely of the common kind, and in Mr. Thornton's stock of common and pied peacocks. It is remarkable that in these two latter instances the black-shouldered kind, though a smaller and weaker bird, increased, "to the extinction of the previously existing breed." I have also received through Mr. Sclater a statement from Mr. Hudson Gurney that he reared many years ago a pair of black-shouldered peacocks from the common kind; and another ornithologist, Prof. A. Newton, states that, five or six years ago, a female bird, in all respects similar to the female of the black-shouldered kind, was produced from a stock of common peacocks in his possession, which during more than twenty years had not been crossed with birds of any other strain. Mr. Jenner Weir informs me that a peacock at Blackheath whilst young was white, but as it became older gradually assumed the characters of the black-shouldered variety; both its parents were common peacocks. Lastly, Mr. Canning has given a case of a female of this same variety appearing in Ireland in a flock of the ordinary kind. (8/35. 'The Field' May 6, 1871. I am much indebted to Mr. Canning for information with respect to his birds.) Here, then, we have seven well authenticated cases in Great Britain of japanned birds, having suddenly appeared within recent times in flocks of the common peafowl. This variety must also have formerly appeared in Europe, for Mr. Canning has seen an old picture, and another is referred to in the 'Field,' with this variety represented. These facts seem to me to indicate that the japanned peacock is a strongly marked variety or "sport," which tends at all times and in many places to reappear. This view is supported by the young being at first white like the young of the white breed, which is undoubtedly a variation. If, on the other hand, we believe the japanned peacock to be a distinct species, we must suppose that in all the above cases the common breed had at some former period been crossed by it, but had lost every trace of the cross; yet that the offspring of these birds 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 seven instances in the same country, within no great length of time, to a wolf perfect in every character; and we must further suppose that in two of the cases, the newly produced wolves afterwards spontaneously increased to such an extent as to lead to the extinction of the parent breed of dogs. So remarkable a bird as the P. nigripennis, when first imported, would have realised a large price; it is therefore improbable that it should have been silently introduced and its history subsequently lost. On the whole the evidence seems to me, as it did to Sir R. Heron, to be decisive in favour of the japanned or black-shouldered breed being a variation, induced by some unknown cause. On this view, the case is the most remarkable one ever recorded of the abrupt appearance of a new form, which so closely resembles a true species that it has deceived one of the most experienced of living ornithologists.
THE TURKEY.
It seems fairly well established by Mr. Gould (8/36. 'Proc. Zoolog. Soc.' April 8, 1856 page 61. Prof. Baird believes (as quoted in Tegetmeier 'Poultry Book' 1866 page 269) that our turkeys are descended from a West Indian species now extinct. But besides the improbability of a bird having long ago become extinct in these large and luxuriant islands, it appears (as we shall presently see) that the turkey degenerates in India, and this fact indicates that it was not aboriginally an inhabitant of the lowlands of the tropics.), that the turkey, in accordance with the history of its first introduction, is descended from a wild Mexican form, which had been domesticated by the natives before the discovery of America, and which is now generally ranked as a local race, and not as a distinct species. However this may be, the case deserves notice 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." (8/37. Audubon 'Ornithological Biography' volume 1 1831 pages 4- 13; and 'Naturalist's Library' volume 14 'Birds' page 138.) 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 during many years afterwards, as he informs me, the turkeys in his neighbourhood clearly showed traces of their crossed parentage. We here have an instance of a domestic race being modified by a cross with a distinct wild race or species. F. Michaux (8/38. F. Michaux 'Travels in N. America' 1802 English translation page 217.) suspected in 1802 that the common domestic turkey was not descended from the United States species alone, but likewise from a southern form, and he went so far as to believe that English and French turkeys differed from having different proportions of the blood of the two parent-forms.
English turkeys are smaller than either wild form. They have not varied in any great degree; but there are some breeds which can be distinguished as Norfolks, Suffolks, Whites, and Copper-coloured (or Cambridge), all of which, if precluded from crossing with other breeds propagate their kind truly. Of these kinds, the most distinct is the small, hardy, dull-black Norfolk turkey, of which the chickens are black, occasionally with white patches about the head. The other breeds scarcely differ except in colour, and their chickens are generally mottled all over with brownish-grey. (8/39. 'Ornamental Poetry' by the Rev. E.S. Dixon 1848 page 34.) 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. (8/40. Bechstein 'Naturgesch. Deutschlands' b. 3 1793 s. 309.) Albin in 1738, and Temminck within a much later period, describe a beautiful breed, dusky-yellowish, brown above and white beneath, with a large top- knot of soft plumose feather. The spurs of the male were rudimentary. This breed has been for a long time extinct in Europe; but a living specimen has lately been imported from the east coast of Africa, which still retains the top-knot and the same general colouring and rudimentary spurs. (8/41. Mr. Bartlett in 'Land and Water' October 31, 1868 page 233; and Mr. Tegetmeier in the 'Field' July 17, 1869 page 46.) Mr. Wilmot has described (8/42. 'Gardener's Chronicle' 1852 page 699.) a white turkey-cock having a crest formed of "feathers about four inches long, with bare quills, and a tuft of soft white down growing at the end." Many of the young birds inherited this kind of crest, but afterwards it fell off or was pecked out by the other birds. This is an interesting case, as with care a new breed might probably have been formed; and a top-knot of this nature would have been to a certain extent analogous to that borne by the males in several allied genera, such as Euplocomus, Lophophorus, and Pavo.
Wild turkeys, believed in every instance to have been imported from the United States, have been kept in the parks of Lords Powis, Leicester, Hill, and Derby. The Rev. W.D. Fox procured birds from the two first-named parks, and he informs me that they certainly differed a little from each other in the shape of their bodies and in the barred plumage on their wings. These birds likewise differed from Lord Hill's stock. Some 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 differing slightly from each other, present an analogous case with the wild cattle kept in the several British parks. We must suppose that such differences have resulted from the prevention of free intercrossing between birds ranging over a wide area, and from the changed conditions to which they have been exposed in England. In India the climate has apparently wrought a still greater change in the turkey, for it is described by Mr. Blyth (8/43. E. Blyth 'Annals and Mag. of Nat. Hist.' 1847 volume 20 page 391.) as being much degenerated in size, "utterly incapable of rising on the wing," of a black colour, and "with the long pendulous appendages over the beak enormously developed."
THE GUINEA FOWL.
The domesticated Guinea fowl is now believed by some naturalists to be descended from the Numida ptilorhynca, which inhabits very hot, and, in parts, extremely arid districts in Eastern Africa; consequently it has been exposed in this country to extremely different conditions of life. Nevertheless it has 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. (8/44. Roulin makes this remark in 'Mem. de divers Savans, 1'Acad. des Sciences' tome 6 1835 page 349. Mr. Hill of Spanish Town in a letter to me describes five varieties of the Guinea fowl in Jamaica. I have seen singular pale-coloured varieties imported from Barbadoes and Demerara.) The Guinea fowl has become thoroughly feral in Jamaica and in St. Domingo (8/45. For St. Domingo see M. A. Salle, in 'Proc. Zoolog. Soc.' 1857 page 236. Mr. Hill remarks to me, in his letter, on the colour of the legs of the feral birds in Jamaica.), and has diminished in size; the legs are black, whereas the legs of the aboriginal African bird are said to be grey. This small change is worth notice on account of the often-repeated statement that all feral animals invariably revert in every character to their original type.
THE CANARY BIRD.
As this bird has been recently domesticated, namely, within the last 350 years, its variability deserves notice. It has been crossed with nine or ten other species of Fringillidae, and some of the hybrids are almost completely fertile; but we have no evidence that any distinct breed has originated from such crosses. Notwithstanding the modern domestication of the canary, many varieties have been produced; even before the year 1718 a list of twenty-seven varieties was published in France (8/46. Mr. B.P. Brent 'The Canary, British Finches' etc. pages 21, 30.), and in 1779 a long schedule of the desired qualities was printed by the London Canary Society, so that methodical selection has been practised during 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 (8/47. 'Cottage Gardener' December 11, 1855 page 184: an account is here given of all the varieties. For many measurements of the wild birds, see Mr. E. Vernon Harcourt ibid December 25, 1855 page 223.) 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 top-knotted canaries, and it is a singular fact that, if two top- knotted birds are matched, the young, instead of having very fine top- knots, are generally bald, or even have a wound on their heads. (8/48. Bechstein 'Naturgesch. der Stubenvogel' 1840 s. 243; see s. 252 on the inherited song of Canary-birds. With respect to their baldness see also W. Kidd 'Treatise on Song-Birds.') It would appear as if the top-knot were due to some morbid condition, which is increased to an injurious degree when two birds in this state are paired. There is a feather-footed breed, and another with a kind of frill running down the breast. One other character deserves notice from being confined to one period of life, and from being strictly inherited at the same period; namely, the wing and tail feathers in prize canaries being black, "but this colour is retained only until the first moult; once moulted, the peculiarity ceases." (8/49. W. Kidd 'Treatise on Song-Birds' page 18.) Canaries differ much in disposition and character, and in some small degree in song. They produce eggs three or four times during the year.
