With respect to the period of life at which the characters proper to each breed first appear, it is obvious that such structures as additional toes must be formed long before birth. In Polish fowls, the extraordinary protuberance of the anterior part of the skull is well developed before the chickens come out of the egg (7/40. As I hear from Mr. Tegetmeier; see also "Proc. Zoolog. Soc." 1856 page 366. On the late development of the crest see "Poultry Chronicle" volume 2 page 132.) but the crest, which is supported on the protuberance, is at first feebly developed, nor does it attain its full size until the second year. The Spanish c.o.c.k is pre-eminent for his magnificent comb, and this is developed at an unusually early age; so that the young males can be distinguished from the females when only a few weeks old, and therefore earlier than in other breeds; they likewise crow very early, namely, when about six weeks old. In the Dutch sub-breed of the Spanish fowl the white ear-lappets are developed earlier than in the common Spanish breed. (7/41. On these points see "Poultry Chronicle" volume 3 page 166; and Tegetmeier "Poultry Book" 1866 pages 105 and 121.) Cochins are characterised by a small tail, and in the young c.o.c.ks the tail is developed at an unusually late period. (7/42. Dixon "Ornamental and Domestic Poultry" page 273.) Game fowls are notorious for their pugnacity; and the young c.o.c.ks crow, clap their little wings, and fight obstinately with each other, even whilst under their mother"s care. (7/43. Ferguson on "Rare and Prize Poultry" page 261.) "I have often had," says one author (7/44. Mowbray on "Poultry" 7th edition 1834 page 13.), "whole broods, scarcely feathered, stone-blind from fighting; the rival couples moping in corners, and renewing their battles on obtaining the first ray of light."
The weapons and pugnacity of all male gallinaceous birds evidently serve the purpose of gaining possession of the females; so that the tendency in our Game chickens to fight at an extremely early age is not only useless, but injurious, as they suffer much from their wounds. The training for battle during an early age may be natural to the wild Gallus bankiva; but as man during many generations has gone on selecting the most obstinately pugnacious c.o.c.ks, it is more probable that their pugnacity has been unnaturally increased, and unnaturally transferred to the young male chickens. In the same manner, it is probable that the extraordinary development of the comb in the Spanish c.o.c.k has been unintentionally transferred to the young c.o.c.ks; for fanciers would not care whether their young birds had large combs, but would select for breeding the adults which had the finest combs, whether or not developed at an early period. The last point which need here be noticed is that, though the chickens of Spanish and Malay fowls are well covered with down, the true feathers are acquired at an unusually late age; so that for a time the young birds are partially naked, and are liable to suffer from cold.
SECONDARY s.e.xUAL CHARACTERS.
The two s.e.xes in the parent-form, the Gallus bankiva, differ much in colour. In our domestic breeds the difference is never greater, but is often less, and varies much in degree even in the sub-breeds of the same main breed. Thus in certain Game fowls the difference is as great as in the parent-form, whilst in the black and white sub-breeds there is no difference in plumage. Mr. Brent informs me that he has seen two strains of black-breasted red Games, of which the c.o.c.ks could not be distinguished, whilst the hens in one were partridge-brown and in the other fawn-brown. A similar case has been observed in the strains of the brown-breasted red Game. The hen of the "duck-winged Game" is "extremely beautiful," and differs much from the hens of all the other Game sub-breeds; but generally, as with the blue and grey Game and with some sub-varieties of the pile- game, a moderately close relation may be observed between the males and females in the variation of their plumage. (7/45. See the full description of the varieties of the Game-breed in Tegetmeier "Poultry Book" 1866 page 131. For Cuckoo Dorkings page 97.) A similar relation is also evident when we compare the several varieties of Cochins. In the two s.e.xes of gold and silver-spangled and of buff Polish fowls, there is much general similarity in the colouring and marks of the whole plumage, excepting of course in the hackles, crest, and beard. In spangled Hamburghs, there is likewise a considerable degree of similarity between the two s.e.xes. In pencilled Hamburghs, on the other hand, there is much dissimilarity; the pencilling which is characteristic of the hens being almost absent in the males of both the golden and silver varieties. But, as we have already seen, it cannot be given as a general rule that male fowls never have pencilled feathers, for Cuckoo Dorkings are "remarkable from having nearly similar markings in both s.e.xes."
It is a singular fact that the males in certain sub-breeds have lost some of their secondary masculine characters, and from their close resemblance in plumage to the females, are often called hennies. There is much diversity of opinion whether these males are in any degree sterile; that they sometimes are partially sterile seems clear (7/46. Mr. Hewitt in Tegetmeier "Poultry Book" 1866 pages 246 and 156. For hen-tailed game-c.o.c.ks see page 131.), but this may have been caused by too close interbreeding.
That they are not quite sterile, and that the whole case is widely different from that of old females a.s.suming masculine characters, is evident from several of these hen-like sub-breeds having been long propagated. The males and females of gold and silver-laced Sebright Bantams can be barely distinguished from each other, except by their combs, wattles, and spurs, for they are coloured alike, and the males have not hackles, nor the flowing sickle-like tail-feathers. A hen-tailed sub-breed of Hamburghs was recently much esteemed. There is also a breed of Game- fowls, in which the males and females resemble each other so closely that the c.o.c.ks have often mistaken their hen-feathered opponents in the c.o.c.k-pit for real hens, and by the mistake have lost their lives. (7/47. "The Field"
April 20, 1861. The writer says he has seen half-a-dozen c.o.c.ks thus sacrificed.) The c.o.c.ks, though dressed in the feathers of the hen, "are high-spirited birds, and their courage has been often proved:" an engraving even has been published of one celebrated hen-tailed victor. Mr. Tegetmeier (7/48. "Proceedings of Zoolog. Soc." March 1861 page 102. The engraving of the hen-tailed c.o.c.k just alluded to was exhibited before the Society.) has recorded the remarkable case of a brown-breasted red Game c.o.c.k which, after a.s.suming its perfect masculine plumage, became hen-feathered in the autumn of the following year; but he did not lose voice, spurs, strength, nor productiveness. This bird has now retained the same character during five seasons, and has begot both hen-feathered and male-feathered offspring. Mr.
Grantley F. Berkeley relates the still more singular case of a celebrated strain of "polecat Game fowls," which produced in nearly every brood a single hen-c.o.c.k. "The great peculiarity in one of these birds was that he, as the seasons succeeded each other, was not always a hen-c.o.c.k, and not always of the colour called the polecat, which is black. From the polecat and hen-c.o.c.k feather in one season he moulted to a full male-plumaged black-breasted red, and in the following year he returned to the former feather." (7/49. "The Field" April 20, 1861.)
I have remarked in my "Origin of Species" that secondary s.e.xual characters are apt to differ much in the species of the same genus, and to be unusually variable in the individuals of the same species. So it is with the breeds of the fowl, as we have already seen, as far as the colour of plumage is concerned, and so it is with the other secondary s.e.xual characters. Firstly, the comb differs much in the various breeds (7/50. I am much indebted to Mr. Brent for an account, with sketches, of all the variations of the comb known to him, and likewise with respect to the tail as presently to be given), and its form is eminently characteristic of each kind, with the exception of the Dorkings, in which the form has not been as yet determined on by fanciers, and fixed by selection. A single, deeply- serrated comb is the typical and most common form. It differs much in size, being immensely developed in Spanish fowls; and in a local breed called Red-caps, it is sometimes "upwards of three inches in breadth at the front, and more than four inches in length, measured to the end of the peak behind." (7/51. The "Poultry Book" by Tegetmeier 1866 page 234.) In some breeds the comb is double, and when the two ends are cemented together it forms a "cup-comb;" in the "rose-comb" it is depressed, covered with small projections, and produced backwards; in the horned and creve-coeur fowl it is produced into two horns; it is triple in the pea-combed Brahmas, short and truncated in the Malays, and absent in the Guelderlands. In the ta.s.selled Game a few long feathers rise from the back of the comb: in many breeds a crest of feathers replaces the comb. The crest, when little developed, arises from a fleshy ma.s.s, but, when much developed, from a hemispherical protuberance of the skull. In the best Polish fowls it is so largely developed, that I have seen birds which could hardly pick up their food; and a German writer a.s.serts (7/52. "Die Huhner- und Pfauenzucht" 1827 s. 11.) that they are in consequence liable to be struck by hawks.
Monstrous structures of this kind would thus be suppressed in a state of nature. The wattles, also, vary much in size, being small in Malays and some other breeds; in certain Polish sub-breeds they are replaced by a great tuft of feathers called a beard.
The hackles do not differ much in the various breeds, but are short and stiff in Malays, and absent in Hennies. As in some orders male birds display extraordinarily-shaped feathers, such as naked shafts with discs at the end, etc., the following case may be worth giving. In the wild Gallus bankiva and in our domestic fowls, the barbs which arise from each side of the extremities of the hackles are naked or not clothed with barbules, so that they resemble bristles; but Mr. Brent sent me some scapular hackles from a young Birchen Duckwing Game c.o.c.k, in which the naked barbs became densely re-clothed with barbules towards their tips; so that these tips, which were dark coloured with a metallic l.u.s.tre, were separated from the lower parts by a symmetrically-shaped transparent zone formed of the naked portions of the barbs. Hence the coloured tips appeared like little separate metallic discs.
The sickle-feathers in the tail, of which there are three pair, and which are eminently characteristic of the male s.e.x, differ much in the various breeds. They are scimitar-shaped in some Hamburghs, instead of being long and flowing as in the typical breeds. They are extremely short in Cochins, and are not at all developed in Hennies. They are carried, together with the whole tail, erect in Dorkings and Gaines; but droop much in Malays and in some Cochins. Sultans are characterised by an additional number of lateral sickle-feathers. The spurs vary much, being placed higher or lower on the shank; being extremely long and sharp in Games, and blunt and short in Cochins. These latter birds seem aware that their spurs are not efficient weapons; for though they occasionally use them, they more frequently fight, as I am informed by Mr. Tegetmeier, by seizing and shaking each other with their beaks. In some Indian Game c.o.c.ks, received by Mr. Brent from Germany, there are, as he informs me, three, four, or even five spurs on each leg. Some Dorkings also have two spurs on each leg (7/53. "Poultry Chronicle" volume 1 page 595. Mr. Brent has informed me of the same fact. With respect to the position of the spurs in Dorkings see "Cottage Gardener" September 18, 1860 page 380.); and in birds of this breed the spur is often placed almost on the outside of the leg. Double spurs are mentioned in an ancient Chinese Encyclopaedia. Their occurrence may be considered as a case of a.n.a.logous variation, for some wild gallinaceous birds, for instance, the Polyplectron, have double spurs.
Judging from the differences which generally distinguish the s.e.xes in the Gallinaceae, certain characters in our domestic fowls appear to have been transferred from the one s.e.x to the other. In all the species (except in Turnix), when there is any conspicuous difference in plumage between the male and female, the male is always the most beautiful; but in golden- spangled Hamburghs the hen is equally beautiful with the c.o.c.k, and incomparably more beautiful than the hen in any natural species of Gallus; so that here a masculine character has been transferred to the female. On the other hand, in Cuckoo Dorkings and in other cuckoo breeds the pencilling, which in Gallus is a female attribute, has been transferred to the male: nor, on the principle of a.n.a.logous variation, is this transference surprising, as the males in many gallinaceous genera are barred or pencilled. With most of these birds head ornaments of all kinds are more fully developed in the male than in the female; but in Polish fowls the crest or top-knot, which in the male replaces the comb, is equally developed in both s.e.xes. In the males of certain other sub-breeds, which from the hen having a small crest, are called lark-crested, "a single upright comb sometimes almost entirely takes the place of the crest."
(7/54. Dixon "Ornamental and Domestic Poultry" page 320.) From this latter case, and more especially from some facts presently to be given with respect to the protuberance of the skull in Polish fowls, the crest in this breed must be viewed as a feminine character which has been transferred to the male. In the Spanish breed the male, as we know, has an immense comb, and this has been partially transferred to the female, for her comb is unusually large, though not upright. In Game fowls the bold and savage disposition of the male has likewise been largely transferred to the female (7/55. Mr. Tegetmeier informs me that Game hens have been found so combative, that it is now generally the practice to exhibit each hen in a separate pen.); and she sometimes even possesses the eminently masculine character of spurs. Many cases are on record of fertile hens being furnished with spurs; and in Germany, according to Bechstein (7/56.
"Naturgeschichte Deutschlands" b. 3 1793 s. 339, 407.), the spurs in the Silk hen are sometimes very long. He mentions also another breed similarly characterised, in which the hens are excellent layers, but are apt to disturb and break their eggs owing to their spurs.
Mr. Layard (7/57. On the Ornithology of Ceylon in "Annals and Mag. of Nat.
History." 2nd series volume 14 1854 page 63.) has given an account of a breed of fowls in Ceylon with black skin, bones, and wattle, but with ordinary feathers, and which cannot "be more aptly described than by comparing them to a white fowl drawn down a sooty chimney; it is, however,"
adds Mr. Layard, "a remarkable fact that a male bird of the pure sooty variety is almost as rare as a tortoise-sh.e.l.l tom-cat." Mr. Blyth found the same rule to hold good with this breed near Calcutta. The males and females, on the other hand, of the black-boned European breed, with silky feathers, do not differ from each other; so that in the one breed, black skin and bones and the same kind of plumage are common to both s.e.xes, whilst in the other breed, these characters are confined to the female s.e.x.
At the present day all the breeds of Polish fowls have the great bony protuberance on their skulls, which includes part of the brain and supports the crest, equally developed in both s.e.xes. But formerly in Germany the skull of the hen alone was protuberant: Blumenbach (7/58. "Handbuch der vergleich. Anatomie" 1805 page 85 note. Mr. Tegetmeier, who gives in "Proc.
Zoolog. Soc." November 25, 1856 a very interesting account of the skulls of Polish fowls, not knowing of Bechstein"s account, has disputed the accuracy of Blumenbach"s statement. For Bechstein see "Naturgeschichte Deutschlands"
b. 3 1793 s. 399 note. I may add that at the first exhibition of Poultry at the Zoological Gardens in May 1845 I saw some fowls, called Friezland fowls, of which the hens were crested, and the c.o.c.ks furnished with a comb.), who particularly attended to abnormal peculiarities in domestic animals, states, in 1805, that this was the case; and Bechstein had previously, in 1793 observed the same fact. This latter author has carefully described the effects on the skull of a crest not only in the case of fowls, but of ducks, geese, and canaries. He states that with fowls, when the crest is not much developed, it is supported on a fatty ma.s.s; but when much developed, it is always supported on a bony protuberance of variable size. He well describes the peculiarities of this protuberance; he attended also to the effects of the modified shape of the brain on the intellect of these birds, and disputes Pallas" statement that they are stupid. He then expressly remarks that he never observed this protuberance in male fowls. Hence there can be no doubt that this extraordinary character in the skulls of Polish fowls was formerly in Germany confined to the female s.e.x, but has now been transferred to the males, and has thus become common to both s.e.xes.
[EXTERNAL DIFFERENCES, NOT CONNECTED WITH THE s.e.xES, BETWEEN THE BREEDS AND BETWEEN INDIVIDUAL BIRDS.
The size of the body differs greatly. Mr. Tegetmeier has known a Brahma to weigh 17 pounds; a fine Malay c.o.c.k 10 pounds; whilst a first-rate Sebright Bantam weighs hardly more than 1 pound. During the last 20 years the size of some of our breeds has been largely increased by methodical selection, whilst that of other breeds has been much diminished. We have already seen how greatly colour varies even within the same breed; we know that the wild G. bankiva varies slightly in colour; we know that colour is variable in all our domestic animals; nevertheless some eminent fanciers have so little faith in variability, that they have actually argued that the chief Game sub-breeds, which differ from each other in nothing but colour, are descended from distinct wild species! Crossing often causes strange modification of colour. Mr. Tegetmeier informs me that when buff and white Cochins are crossed, some of the chickens are almost invariably black.
According to Mr. Brent, black and white Cochins occasionally produce chickens of a slaty-blue tint; and this same tint results, as Mr.
Tegetmeier tells me, from crossing white Cochins with black Spanish fowls, or white Dorkings with black Minorcas. (7/59. "Cottage Gardener" January 3, 1860 page 218.) A good observer (7/60. Mr. Williams in a paper read before the Dublin Nat. Hist. Soc. quoted in "Cottage Gardener" 1856 page 161.) states that a first-rate silver-spangled Hamburgh hen gradually lost the most characteristic qualities of the breed, for the black lacing to her feathers disappeared, and her legs changed from leaden-blue to white: but what makes the case remarkable is, that this tendency ran in the blood for her sister changed in a similar but less strongly marked manner; and chickens produced from this latter hen were at first almost pure white, "but on moulting acquired black colours and some spangled feathers with almost obliterated markings;" so that a new variety arose in this singular manner. The skin in the different breeds differs much in colour, being white in common kinds, yellow in Malays and Cochins, and black in Silk fowls; thus mocking, as M. G.o.dron (7/61. "De l"Espece" 1859 page 442. For the occurrence of black-boned fowls in South America, see Roulin in "Mem.
de l"Acad. des Sciences" tome 6 page 351; and Azara, "Quadrupedes du Paraguay" tome 2 page 324. A frizzled fowl sent to me from Madras had black bones.) remarks the three princ.i.p.al types of skin in mankind. The same author adds that, as different kinds of fowls living in distant and isolated parts of the world have black skin and bones, this colour must have appeared at various times and places.
The shape and carriage of the body, and the shape of the head differ much.
The beak varies slightly in length and curvature, but incomparably less than with pigeons. In most crested fowls the nostrils offer a remarkable peculiarity in being raised with a crescentic outline. The primary wing- feathers are short in Cochins; in a male, which must have been more than twice as heavy as G. bankiva, these feathers were in both birds of the same length. I have counted, with Mr. Tegetmeier"s aid, the primary wing- feathers in thirteen c.o.c.ks and hens of various breeds; in four of them, namely in two Hamburghs, a Cochin, and Game bantam, there were 10, instead of the normal number 9; but in counting these feathers I have followed the practice of fanciers, and have NOT included the first minute primary feather, barely three-quarters of an inch in length. These feathers differ considerably in relative length, the fourth, or the fifth, or the sixth, being the longest; with the third either equal to, or considerably shorter than the fifth. In wild gallinaceous species the relative length and number of the main wing and tail-feathers are extremely constant.
The tail differs much in erectness and size, being small in Malays and very small in Cochins. In thirteen fowls of various breeds which I have examined, five had the normal number of 14 feathers, including in this number the two middle sickle-feathers; six others (viz., a Caffre c.o.c.k, Gold-spangled Polish c.o.c.k, Cochin hen, Sultan hen, Game hen and Malay hen had 16; and two (an old Cochin c.o.c.k and Malay hen) had 17 feathers. The rumpless fowl has no tail and in one which I possessed there was no oil- gland; but this bird though the os coccygis was extremely imperfect, had a vestige of a tail with two rather long feathers in the position of the outer caudals. This bird came from a family where, as I was told, the breed had kept true for twenty years; but rumpless fowls often produce chickens with tails. (7/62. Mr. Hewitt in Tegetmeier "Poultry Book" 1866 page 231.) An eminent physiologist (7/63. Dr. Broca in Brown-Sequard "Journal de Phys." tome 2 page 361.) has recently spoken of this breed as a distinct species; had he examined the deformed state of the os coccyx he would never have come to this conclusion; he was probably misled by the statement, which may be found in some works, that tailless fowls are wild in Ceylon; but this statement, as I have been a.s.sured by Mr. Layard and Dr. Kellaert who have so closely studied the birds of Ceylon, is utterly false.
The tarsi vary considerably in length, being relatively to the femur considerably longer in the Spanish and Frizzled, and shorter in the Silk and Bantam breeds, than in the wild G. bankiva; but in the latter, as we have seen, the tarsi vary in length. The tarsi are often feathered. The feet in many breeds are furnished with additional toes. Golden-spangled Polish fowls are said (7/64. Dixon "Ornamental Poultry" page 325.) to have the skin between their toes much developed: Mr. Tegetmeier observed this in one bird, but it was not so in one which I examined. Prof. Hoffmann has sent me a sketch of the feet of a fowl of the common breed at Giessen, with a web extending between the three toes, for about a third of their length.
In Cochins the middle toe is said (7/65. "Poultry Chronicle" volume 1 page 485. Tegetmeier "Poultry Book" 1866 page 41. On Cochins grazing ibid page 46.) to be nearly double the length of the lateral toes, and therefore much longer than in G. bankiva or in other fowls; but this was not the case in two which I examined. The nail of the middle toe in this same breed is surprisingly broad and flat, but in a variable degree in two birds which I examined; of this structure in the nail there is only a trace in G.
bankiva.
The voice differs slightly, as I am informed by Mr. Dixon, in almost every breed. The Malays (7/66. Ferguson on "Prize Poultry" page 87.) have a loud, deep, somewhat prolonged crow, but with considerable individual difference.
Colonel Sykes remarks that the domestic Kulm c.o.c.k in India has not the shrill clear pipe of the English bird, and "his scale of notes appears more limited." Dr. Hooker was struck with the "prolonged howling screech" of the c.o.c.ks in Sikhim. (7/67. Col. Sykes in "Proc. Zoolog. Soc." 1832 page 151.
Dr. Hooker"s "Himalayan Journals" volume 1 page 314.) The crow of the Cochin is notoriously and ludicrously different from that of the common c.o.c.k. The disposition of the different breeds is widely different, varying from the savage and defiant temper of the Game-c.o.c.k to the extremely peaceable temper of the Cochins. The latter, it has been a.s.serted, "graze to a much greater extent than any other varieties." The Spanish fowls suffer more from frost than other breeds.]
Before we pa.s.s on to the skeleton, the degree of distinctness of the several breeds from G. bankiva ought to be noticed. Some writers speak of the Spanish as one of the most distinct breeds, and so it is in general aspect; but its characteristic differences are not important. The Malay appears to me more distinct, from its tall stature, small drooping tail with more than fourteen tail-feathers, and from its small comb and wattles; nevertheless, one Malay sub-breed is coloured almost exactly like G.
bankiva. Some authors consider the Polish fowl as very distinct; but this is a semi-monstrous breed, as shown by the protuberant and irregularly perforated skull. The Cochin, from its deeply furrowed frontal bones, peculiarly shaped occipital foramen, short wing-feathers, short tail containing more than fourteen feathers, broad nail to the middle toe, fluffy plumage, rough and dark-coloured eggs, and especially from its peculiar voice, is probably the most distinct of all the breeds. If any one of our breeds has descended from some unknown species, distinct from G.
bankiva, it is probably the Cochin; but the balance of evidence does not favour this view. All the characteristic differences of the Cochin breed are more or less variable, and may be detected in a greater or lesser degree in other breeds. One sub-breed is coloured closely like G. bankiva.
The feathered legs, often furnished with an additional toe, the wings incapable of flight, the extremely quiet disposition, indicate a long course of domestication; and these fowls come from China, where we know that plants and animals have been tended from a remote period with extraordinary care, and where consequently we might expect to find profoundly modified domestic races.
OSTEOLOGICAL DIFFERENCES.
I have examined twenty-seven skeletons and fifty-three skulls of various breeds, including three of G. bankiva: nearly half of these skulls I owe to the kindness of Mr. Tegetmeier, and three of the skeletons to Mr. Eyton.
SKULL.
(FIGURE 33. OCCIPITAL FORAMEN, of natural size. A. Wild Gallus bankiva. B.
Cochin c.o.c.k.
FIGURE 34. SKULLS of natural size, viewed from above, a little obliquely.
A. Wild Gallus bankiva. B. White-crested Polish c.o.c.k.
FIGURE 35. LONGITUDINAL SECTIONS OF SKULL, of natural size, viewed laterally; A. Polish c.o.c.k. B. Cochin c.o.c.k, selected for comparison with the above from being of nearly the same size.
FIGURE 36. SKULL OF HORNED FOWL, of natural size, viewed from above, a little obliquely. (In the possession of Tegetmeier.))
[The SKULL differs greatly in size in different breeds, being nearly twice as long in the largest Cochins, but not nearly twice as broad, as in Bantams. The bones at the base, from the occipital foramen to the anterior end (including the quadrates and pterygoids), are absolutely identical in SHAPE in all the skulls. So is the lower jaw. In the forehead slight differences are often perceptible between the males and females, evidently caused by the presence of the comb. In every case I take the skull of G.
bankiva as the standard of comparison. In four Games, in one Malay hen, in an African c.o.c.k, in a Frizzled c.o.c.k from Madras, in two black-boned Silk hens, no differences worth notice occur. In three SPANISH c.o.c.ks, the form of the forehead between the orbits differs considerably; in one it is considerably depressed, whilst in the two others it is rather prominent, with a deep medial furrow; the skull of the hen is smooth. In three skulls of SEBRIGHT BANTAMS the crown is more globular, and slopes more abruptly to the occiput, than in G. bankiva. In a Bantam or Jumper from Burmah these same characters are more strongly p.r.o.nounced, and the supra-occiput is more pointed. In a black Bantam the skull is not so globular, and the occipital foramen is very large, and has nearly the same sub-triangular outline presently to be described in Cochins; and in this skull the two ascending branches of the premaxillary are overlapped in a singular manner by the processes of the nasal bone, but, as I have seen only one specimen, some of these differences may be individual. Of Cochins and Brahmas (the latter a crossed race approaching closely to Cochins) I have examined seven skulls; at the point where the ascending branches of the premaxillary rest on the frontal bone the surface is much depressed, and from this depression a deep medial furrow extends backwards to a variable distance; the edges of this fissure are rather prominent, as is the top of the skull behind and over the orbits. These characters are less developed in the hens. The pterygoids, and the processes of the lower jaw, are broader, relatively to the size of the head, than in G. bankiva; and this is likewise the case with Dorkings when of large size. The fork of the hyoid bone in Cochins is twice as wide as in G. bankiva, whereas the length of the other hyoid bones is only as three to two. But the most remarkable character is the shape of the occipital foramen: in G. bankiva (A) the breadth in a horizontal line exceeds the height in a vertical line, and the outline is nearly circular; whereas in Cochins (B) the outline is sub-triangular, and the vertical line exceeds the horizontal line in length. This same form likewise occurs in the black Bantam above referred to, and an approach to it may be seen in some Dorkings, and in a slight degree in certain other breeds.
Of Dorkings I have examined three skulls, one belonging to the white-sub- breed; the one character deserving notice is the breadth of the frontal bones, which are moderately furrowed in the middle; thus in a skull which was less than once and a half the length of that of G. bankiva, the breadth between the orbits was exactly double. Of Hamburghs I have examined four skulls (male and female) of the pencilled sub-breed, and one (male) of the spangled sub-breed; the nasal bones stand remarkably wide apart, but in a variable degree; consequently narrow membrane-covered s.p.a.ces are left between the tips of the two ascending branches of the pre-maxillary bones, which are rather short, and between these branches and the nasal bones. The surface of the frontal bone, on which the branches of the premaxillary rest, is very little depressed. These peculiarities no doubt stand in close relation with the broad, flattened rose-comb characteristic of the Hamburgh breed.
I have examined fourteen skulls of POLISH AND OTHER CRESTED BREEDS. Their differences are extraordinary. First for nine skulls of different sub- breeds of English Polish fowls. The hemispherical protuberance of the frontal bones (7/68. See Mr. Tegetmeier"s account with woodcuts of the skull of Polish fowls in "Proc. Zoolog. Soc." November 25, 1856. For other references see Isid. Geoffroy Saint-Hilaire "Hist. Gen. des Anomalies" tome 1 page 287. M. C. Dareste suspects ("Recherches sur les Conditions de la Vie" etc. Lille 1863 page 36) that the protuberance is not formed by the frontal bones, but by the ossification of the dura mater.) may be seen in figure 34, in which (B) the skull of a white-crested Polish fowl is shown obliquely from above, with the skull (A) of (G. bankiva in the same position. In figure 35 longitudinal sections are given of the skull of a Polish fowl, and, for comparison, of a Cochin of the same size. The protuberance in all Polish fowls occupies the same position but differs much in size. In one of my nine specimens it was extremely slight. The degree to which the protuberance is ossified varies greatly, larger or smaller portions of bone being replaced by membrane. In one specimen there was only a single open pore; generally, there are many variously shaped open s.p.a.ces, the bone forming an irregular reticulation. A medial, longitudinal, arched ribbon of bone is generally retained, but in one specimen there was no bone whatever over the whole protuberance, and the skull, when cleaned and viewed from above, presented the appearance of an open basin. The change in the whole internal form of the skull is surprisingly great. The brain is modified in a corresponding manner, as is shown in the two longitudinal sections, which deserve attentive consideration. The upper and anterior cavity of the three into which the skull may be divided, is the one which is so greatly modified; it is evidently much larger than in the Cochin skull of the same size, and extends much further beyond the interorbital septum, but laterally is less deep. This cavity, as I hear from Mr. Tegetmeier, is entirely filled with brain. In the skull of the Cochin and of all ordinary fowls a strong internal ridge of bone separates the anterior from the central cavity; but this ridge is quite absent in the Polish skull here figured. The shape of the central cavity is circular in the Polish, and lengthened in the Cochin skull. The shape of the posterior cavity, together with the position, size, and number of the pores for the nerves, differ much in these two skulls. A pit deeply penetrating the occipital bone of the Cochin is entirely absent in this Polish skull, whilst in another specimen it was well developed. In this second specimen the whole internal surface of the posterior cavity likewise differs to a certain extent in shape. I made sections of two other skulls,--namely, of a Polish fowl with the protuberance singularly little developed, and of a Sultan in which it was a little more developed; and when these two skulls were placed between the two above figured (figure 35), a perfect gradation in the configuration of each part of the internal surface could be traced. In the Polish skull, with a small protuberance, the ridge between the anterior and middle cavities was present, but low; and in the Sultan this ridge was replaced by a narrow furrow standing on a broad raised eminence.
It may naturally be asked whether these remarkable modifications in the form of the brain affect the intellect of Polish fowls; some writers have stated that they are extremely stupid, but Bechstein and Mr. Tegetmeier have shown that this is by no means generally the case. Nevertheless Bechstein (7/69. "Naturgeschichte Deutschlands" b. 3 1793 s. 400.) states that he had a Polish hen which "was crazy, and anxiously wandered about all day long." A hen in my possession was solitary in her habits, and was often so absorbed in reverie that she could be touched; she was also deficient in the most singular manner in the faculty of finding her way, so that, if she strayed a hundred yards from her feeding-place, she was completely lost, and would then obstinately try to proceed in a wrong direction. I have received other and similar accounts of Polish fowls appearing stupid or half-idiotic. (7/70. The "Field" May 11, 1861. I have received communications to a similar effect from Messrs. Brent and Tegetmeier.)
To return to the skull of Polish fowls. The posterior part, viewed externally, differs little from that of G. bankiva. In most fowls the posterior-lateral process of the frontal bone and the process of the squamosal bone run together and are ossified near their extremities: this union of the two bones, however, is not constant in any breed; and in eleven out of fourteen skulls of crested breeds, these processes were quite distinct. These processes, when not united, instead of being inclined anteriorly, as in all common breeds, descend at right angles to the lower jaw; and in this case the longer axis of the bony cavity of the ear is likewise more perpendicular, than in other breeds. When the squamosal process is free instead of expanding at the tip, it is reduced to an extremely fine and pointed style, of variable length. The pterygoid and quadrate bones present no differences. The palatine bones are a little more curved upwards at their posterior ends. The frontal bones, anteriorly to the protuberance, are, as in Dorkings, very broad, but in a variable degree. The nasal bones either stand far apart, as in Hamburghs, or almost touch each other, and in one instance were ossified together. Each nasal bone properly sends out in front two long processes of equal lengths, forming a fork; but in all the Polish skulls, except one, the inner process was considerably, but in a variable degree, shortened and somewhat upturned. In all the skulls, except one, the two ascending branches of the premaxillary, instead of running up between the processes of the nasal bones and resting on the ethmoid bone, are much shortened and terminate in a blunt, somewhat upturned point. In those skulls in which the nasal bones approach quite close to each other or are ossified together, it would be impossible for the ascending branches of the premaxillary to reach the ethmoid and frontal bones; hence we see that even the relative connection of the bones has been changed. Apparently in consequence of the branches of the premaxillary and of the inner processes of the nasal bones being somewhat upturned, the external orifices of the nostrils are upraised and a.s.sume a crescentic outline.
I must still say a few words on some of the foreign Crested breeds. The skull of a crested, rumpless, white Turkish fowl was very slightly protuberant, and but little perforated; the ascending branches of the premaxillary were well developed. In another Turkish breed, called Ghoondooks, the skull was considerably protuberant and perforated; the ascending branches of the premaxillary were so much aborted that they projected only 1/15th of an inch; and the inner processes of the nasal bone were so completely aborted, that the surface where they should have projected was quite smooth. Here then we see these two bones modified to an extreme degree. Of Sultans (another Turkish breed) I examined two skulls; in that of the female the protuberance was much larger than in the male. In both skulls the ascending branches of the premaxillary were very short, and in both the nasal portion of the inner processes of the nasal bones were ossified together. These Sultan skulls differed from those of English Polish fowls in the frontal bones, anteriorly to the protuberance, not being broad.
The last skull which I need describe is a unique one, lent to me by Mr.
Tegetmeier: it resembles a Polish skull in most of its characters, but has not the great frontal protuberance; it has, however, two rounded k.n.o.bs of a different nature, which stand more in front, above the lachrymal bones.
These curious k.n.o.bs, into which the brain does not enter, are separated from each other by a deep medial furrow; and this is perforated by a few minute pores. The nasal bones stand rather wide apart, with their inner processes, and the ascending branches of the premaxillary, upturned and shortened. The two k.n.o.bs no doubt supported the two great horn-like projections of the comb.
From the foregoing facts we see in how astonishing a manner some of the bones of the skull vary in Crested fowls. The protuberance may certainly be called in one sense a monstrosity, as being wholly unlike anything observed in nature: but as in ordinary cases it is not injurious to the bird, and as it is strictly inherited, it can hardly in another sense be called a monstrosity. A series may be formed commencing with the black-boned Silk fowl, which has a very small crest with the skull beneath penetrated only by a few minute orifices, but with no other change in its structure; and from this first stage we may proceed to fowls with a moderately large crest, which rests, according to Bechstein, on a fleshy ma.s.s, but without any protuberance in the skull. I may add that I have seen a similar fleshy or fibrous ma.s.s beneath the tuft of feathers on the head of the Tufted duck; and in this case there was no actual protuberance in the skull, but it had become a little more globular. Lastly, when we come to fowls with a largely developed crest, the skull becomes largely protuberant and is perforated by a mult.i.tude of irregular open s.p.a.ces. The close relation between the crest and the size of the bony protuberance is shown in another way; for Mr. Tegetmeier informs me that if chickens lately hatched be selected with a large bony protuberance, when adult they will have a large crest. There can be no doubt that in former times the breeder of Polish fowls attended solely to the crest, and not to the skull; nevertheless, by increasing the crest, in which he has been wonderfully successful, he has unintentionally made the skull protuberant to an astonishing degree; and through correlation of growth, he has at the same time affected the form and relative connexion of the premaxillary and nasal bones, the shape of the orifice of the nose, the breadth of the frontal bones, the shape of the post-lateral processes of the frontal and squamosal bones, the direction of the axis of the bony cavity of the ear, and lastly the internal configuration of the whole skull together with the shape of the brain.
VERTEBRAE.
(FIGURE 37. SIXTH CERVICAL VERTEBRA, natural size, viewed laterally. A.
Wild Gallus bankiva. B. Cochin c.o.c.k.)
In G. bankiva there are fourteen cervical, seven dorsal with ribs, apparently fifteen lumbar and sacral, and six caudal vertebrae (7/71. It appears that I have not correctly designated the several groups of vertebrae, for a great authority, Mr. W.K. Parker ("Transact. Zoolog. Soc."
volume 5 page 198) specifies 16 cervical, 4 dorsal, 15 lumbar, and 6 caudal vertebrae in this genus. But I have used the same terms in all the following descriptions.); but the lumbar and sacral are so much anchylosed that I am not sure of their number, and this makes the comparison of the total number of vertebrae in the several breeds difficult. I have spoken of six caudal vertebrae, because the basal one is almost completely anchylosed with the pelvis; but if we consider the number as seven, the caudal vertebrae agree in all the skeletons. The cervical vertebrae are, as just stated, in appearance fourteen; but out of twenty-three skeletons in a fit state for examination, in five of them, namely, in two Games, in two pencilled Hamburghs, and in a Polish, the fourteenth vertebra bore ribs, which, though small, were perfectly developed with a double articulation.
The presence of these little ribs cannot be considered as a fact of much importance, for all the cervical vertebrae bear representatives of ribs; but their development in the fourteenth vertebra reduces the size of the pa.s.sages in the transverse processes, and makes this vertebra exactly like the first dorsal vertebra. The addition of these little ribs does not affect the fourteenth cervical alone, for properly the ribs of the first true dorsal vertebra are dest.i.tute of processes; but in some of the skeletons in which the fourteenth cervical bore little ribs the first pair of true ribs had well-developed processes. When we know that the sparrow has only nine, and the swan twenty-three cervical vertebrae (7/72.
Macgillivray "British Birds" volume 1 page 25.), we need feel no surprise at the number of the cervical vertebrae in the fowl being, as it appears, variable.