in the same twenty-five birds, now gave a widely different result; for they were proportionally with those of the rock-pigeon too short in seventeen birds, and in only eight too long. Of these eight birds, five were long-beaked,[39] and this fact perhaps indicates that there is some correlation of the length of the beak with the length of the bones of the wings, in the same manner as with that of the feet and tarsi. The shortening of the humerus and radius in the seventeen birds may probably be attributed to disuse, as in the case of the scapula and furculum to which the wing-bones are attached;—the lengthening of the wing-feathers, and consequently the expansion of the wings from tip to tip, being, on the other hand, as completely independent of use and disuse as is the growth of the hair or wool on our long-haired dogs or long-woolled sheep.
To sum up: we may confidently admit that the length of the sternum, and frequently the prominence of its crest, the length of the scapula and furculum, have all been reduced in size in comparison with the same parts in the rock-pigeon. And I presume that this may be attributed to disuse or lessened exercise. The wings, as measured from the ends of the radii, have likewise been generally reduced in length; but, owing to the increased growth of the wing-feathers, the wings, from tip to tip, are commonly longer than in the rock-pigeon. The feet, as well as the tarsi conjointly with the middle toe, have likewise in most cases become reduced; and this it is probable has been caused by their lessened use; but the existence of some sort of correlation between the feet and beak is shown more plainly than the effects of disuse. We have also some faint indication of a similar correlation between the main bones of the wing and the beak.
_Summary on the Points of Difference between the several Domestic Races, and between the individual Birds._—The beak, together with the bones of the face, differ remarkably in length, breadth, shape, and curvature. The skull differs in shape, and greatly in the angle formed by the union of the pre-maxillary, nasal, and maxillo-jugal bones. The curvature of the lower jaw and the reflection of its upper margin, as well as the gape of the mouth, differ in a highly remarkable manner.
The tongue varies much in length, both independently and in correlation with the length of the beak. The development of the naked, wattled skin over the nostrils and round the eyes varies in an extreme degree. The eyelids and the external orifices of the nostrils vary in length, and are to a certain extent correlated with the degree of development of the wattle. The size and form of the œsophagus and crop, and their capacity for inflation, differ immensely. The length of the neck varies. With the varying shape of the body, the breadth and number of the ribs, the presence of processes, the number of the sacral vertebræ, and the length of the sternum, all vary. The number and size of the coccygeal vertebræ vary, apparently in correlation with the increased size of the tail. The size and shape of the perforations in the sternum, and the size and divergence of the arms of the furculum, differ. The oil-gland varies in development, and is sometimes quite aborted. The direction and length of certain feathers have been much modified, as in the hood of the Jacobin and the frill of the Turbit.
The wing and tail-feathers generally vary in length together, but sometimes independently of each other and of the size of the body. The number and position of the tail-feather vary to an unparalleled degree.
The primary and secondary wing-feathers occasionally vary in number, apparently in correlation with the length of the wing. The length of the leg and the size of the feet, and, in connection with the latter, the number of the scutellæ, all vary. A web of skin sometimes connects the bases of the two inner toes, and almost invariably the two outer toes when the feet are feathered.
The size of the body differs greatly: a Runt has been known to weigh more than five times as much as a Short-faced Tumbler. The eggs differ in size and shape. According to Parmentier,[40] some races use much straw in building their nests, and others use little; but I cannot hear of any recent corroboration of this statement. The length of time required for hatching the eggs is uniform in all the breeds. The period at which the characteristic plumage of some breeds is acquired, and at which certain changes of colour supervene, differs. The degree to which the young birds are clothed with down when first hatched is different, and is correlated in a singular manner with the colour of the plumage. The manner of flight, and certain inherited movements, such as clapping the wings, tumbling either in the air or on the ground, and the manner of courting the female, present the most singular differences. In disposition the several races differ. Some races are very silent; others coo in a highly peculiar manner.
Although many different races have kept true in character during several centuries, as we shall hereafter more fully see, yet there is far more individual variability in the most constant breeds than in birds in a state of nature. There is hardly any exception to the rule that those characters vary most which are now most valued and attended to by fanciers, and which consequently are now being improved by continued selection. This is indirectly admitted by fanciers when they complain that it is much more difficult to breed high fancy pigeons up to the proper standard of excellence than the so-called toy pigeons, which differ from each other merely in colour; for particular colours when once acquired are not liable to continued improvement or augmentation. Some characters become attached, from quite unknown causes, more strongly to the male than to the female sex; so that we have in certain races, a tendency towards the appearance of secondary sexual characters,[41] of which the aboriginal rock-pigeon displays not a trace.
[1] The Hon. C. Murray has sent me some very valuable specimens from Persia; and H.M. Consul, Mr. Keith Abbott, has given me information on the pigeons of the same country. I am deeply indebted to Sir Walter Elliot for an immense collection of skins from Madras, with much information regarding them. Mr. Blyth has freely communicated to me his stores of knowledge on this and all other related subjects. The Rajah Sir James Brooke sent me specimens from Borneo, as has H.M.
Consul, Mr. Swinhoe, from Amoy in China, and Dr. Daniell from the west coast of Africa.
[2] Mr. B. P. Brent, well known for his various contributions to poultry literature, has aided me in every way during several years: so has Mr. Tegetmeier, with unwearied kindness. This latter gentleman, who is well known for his works on poultry, and who has largely bred pigeons, has looked over this and the following chapters. Mr. Bult formerly showed me his unrivalled collection of Pouters, and gave me specimens. I had access to Mr. Wicking’s collection, which contained a greater assortment of kinds than could anywhere else be seen; and he has always aided me with specimens and information given in the freest manner. Mr. Haynes and Mr. Corker have given me specimens of their magnificent Carriers. To Mr. Harrison Weir I am likewise indebted. Nor must I by any means pass over the assistance received from Mr. J. M.
Eaton, Mr. Baker, Mr. Evans, and Mr. J. Baily, jun., of Mount-street—to the latter gentleman I have been indebted for some valuable specimens. To all these gentlemen I beg permission to return my sincere and cordial thanks.
[3] ‘Les Pigeons de Volière et de Colombier’ Paris 1824. During forty-five years the sole occupation of M. Corbié was the care of the pigeons belonging to the Duchess of Berry. Bonizzi has described a large number of coloured varieties in Italy: ‘Le variazioni dei colombi Domestici,’ Padova, 1873.
Paris, 1855. This author makes 288 species, ranked under 85 genera.
[5] As I so often refer to the size of the _C. livia,_ or rock-pigeon, it may be convenient to give the mean between the measurements of two wild birds, kindly sent me by Dr. Edmondstone from the Shetland Islands.
Inches From feathered base of beak to end of tail: 14·25 From feathered base of beak to oil-gland: 9·50 From tip of beak to end of tail: 15·02 Of tail-feathers: 4·62 From tip to tip of wing: 26·75 Of folded wing: 9·25 Beak: Length from tip of beak to feathered base: ·77 Thickness, measured vertically at distal end of nostrils: ·23 Breadth, measured at same place: ·16 Feet: From end of middle toe (without claw) to distal end of tibia: 2·77 From end of middle toe to end of hind toe (without claws): 2·02 Weight: 14-1/4 ounces.
[6] This drawing was made from a dead bird. The six following figures were drawn with great care by Mr. Luke Wells from living birds selected by Mr. Tegetmeier. It may be confidently asserted that the characters of the six breeds which have been figured are not in the least exaggerated.
[10] This treatise was written by Sayzid Mohammed Musari, who died in 1770: I owe to the great kindness of Sir W. Elliot a translation of this curious treatise.
[12] ‘Annals and Mag. of Nat. History,’ vol. xix, 1847, p. 105.
[13] This gland occurs in most birds; but Nitzsch (in his ‘Pterylographie,’ 1840, p. 55) states that it is absent in two species of Columba, in several species of Psittacus, in some species of Otis, and in most or all birds of the Ostrich family. It can hardly be an accidental coincidence that the two species of Columba, which are destitute of an oil-gland, have an unusual number of tail-feathers, namely 16, and in this respect resemble Fantails.
[14] _See_ the two excellent editions published by Mr. J. M. Eaton in 1852 and 1858, entitled ‘A Treatise on Fancy Pigeons.’
[15] English translation, by F. Gladwin, 4th edition, vol. i. The habit of the Lotan is also described in the Persian treatise before alluded to, published about 100 years ago: at this date the Lotans were generally white and crested as at present. Mr. Blyth describes these birds in ‘Annals and Mag. of Nat. Hist.,’ vol. xiv., 1847, p.
104; he says that they “may be seen at any of the Calcutta bird-dealers.”
[17] _See_ the account of the House-tumblers kept at Glasgow, in the [22] Willughby’s ‘Ornithology,’ edited by Ray.
p. 58.
(‘Comptes Rendus’), 1854-55. Mr. Blyth, in ‘Annals of Nat. Hist.,’ vol. xix., 1847, p. 41, mentions, as a very singular fact, “that of the two species of Ectopistes, which are nearly allied to each other, one should have fourteen tail-feathers, while the other, the passenger pigeon of North America, should possess but the usual number—twelve.”
[28] Described and figured in the ‘Poultry Chronicle,’ vol. iii., 1855, p. 82.
_et passim._ ‘Descent of Man’ (6th edit. p. 466) some curious cases, on the authority of Mr. Tegetmeier, of silver-coloured (_i.e._ very pale blue) birds being generally females, and of the ease with which a race thus characterised could be produced. Bonizzi (_see_ ‘Variazioni dei Columbi domestici:’ Padova, 1873) states that certain coloured spots are often different in the two sexes, and the certain tints are commoner in females than in male pigeons.
he knows no species which present any remarkable sexual distinction; but Mr. Wallace informs me, that in the sub-family of the Treronidæ the sexes often differ considerably in colour. _See also_ on sexual differences in the Columbidæ, Gould, ‘Handbook to the Birds of Australia,’ vol. ii., pp. 109-149.
[36] I am not sure that I have designated the different kinds of vertebræ correctly: but I observe that different anatomists follow in this respect different rules, and, as I use the same terms in the comparison of all the skeletons, this, I hope, will not signify.
[38] In an analogous, but converse, manner, certain natural groups of the Columbidæ, from being more terrestrial in their habits than other allied groups, have larger feet. _See_ Prince Bonaparte’s ‘Coup d’œil sur l’Ordre des Pigeons.’
[39] It perhaps deserves notice that besides these five birds two of the eight were Barbs, which, as I have shown, must be classed in the same group with the long-beaked Carriers and Runts. Barbs may properly be called short-beaked Carriers. It would, therefore, appear as if, during the reduction of their beaks, their wings had retained a little of that excess of length which is characteristic of their nearest relations and progenitors.
[40] Temminck, ‘Hist. Nat. Gén. des Pigeons et des Gallinacés,’ tom.
i., 1813, p. 170.
[41] This term was used by John Hunter for such differences in structure between the males and females, as are not directly connected with the act of reproduction, as the tail of the peacock, the horns of deer, etc.
CHAPTER VI. PIGEONS—_continued._ ON THE ABORIGINAL PARENT-STOCK OF THE SEVERAL DOMESTIC RACES—HABITS OF LIFE—WILD RACES OF THE ROCK-PIGEON—Dovecot-PIGEONS—PROOFS OF THE DESCENT OF THE SEVERAL RACES FROM COLUMBA LIVIA—FERTILITY OF THE RACES WHEN CROSSED—REVERSION TO THE PLUMAGE OF THE WILD ROCK-PIGEON—CIRCUMSTANCES FAVOURABLE TO THE FORMATION OF THE RACES—ANTIQUITY AND HISTORY OF THE PRINCIPAL RACES—MANNER OF THEIR FORMATION—SELECTION—UNCONSCIOUS SELECTION—CARE TAKEN BY FANCIERS IN SELECTING THEIR BIRDS—SLIGHTLY DIFFERENT STRAINS GRADUALLY CHANGE INTO WELL-MARKED BREEDS—EXTINCTION OF INTERMEDIATE FORMS—CERTAIN BREEDS REMAIN PERMANENT, WHILST OTHERS CHANGE—SUMMARY.
The differences described in the last chapter between the eleven chief domestic races and between individual birds of the same race, would be of little significance, if they had not all descended from a single wild stock. The question of their origin is therefore of fundamental importance, and must be discussed at considerable length. No one will think this superfluous who considers the great amount of difference between the races, who knows how ancient many of them are, and how truly they breed at the present day. Fanciers almost unanimously believe that the different races are descended from several wild stocks, whereas most naturalists believe that all are descended from the Columba livia or rock-pigeon.
Temminck[1] has well observed, and Mr. Gould has made the same remark to me, that the aboriginal parent must have been a species which roosted and built its nest on rocks; and I may add that it must have been a social bird. For all the domestic races are highly social, and none are known to build or habitually to roost on trees. The awkward manner in which some pigeons, kept by me in a summer-house near an old walnut-tree, occasionally alighted on the barer branches, was evident.[2] Nevertheless, Mr. R. Scot Skirving informs me that he often saw crowds of pigeons in Upper Egypt settling on low trees, but not on palms, in preference to alighting on the mud hovels of the natives. In India Mr. Blyth[3] has been assured that the wild _C. livia,_ var. _intermedia,_ sometimes roosts in trees. I may here give a curious instance of compulsion leading to changed habits: the banks of the Nile above lat. 28° 30′ are perpendicular for a long distance, so that when the river is full the pigeons cannot alight on the shore to drink, and Mr.
Skirving repeatedly saw whole flocks settle on the water, and drink whilst they floated down the stream. These flocks seen from a distance resembled flocks of gulls on the surface of the sea.
If any domestic race had descended from a species which was not social, or which built its nest and roosted in trees,[4] the sharp eyes of fanciers would assuredly have detected some vestige of so different an aboriginal habit. For we have reason to believe that aboriginal habits are long retained under domestication. Thus with the common ass we see signs of its original desert life in its strong dislike to cross the smallest stream of water, and in its pleasure in rolling in the dust. The same strong dislike to cross a stream is common to the camel, which has been domesticated from a very ancient period. Young pigs, though so tame, sometimes squat when frightened, and thus try to conceal themselves even on an open and bare place. Young turkeys, and occasionally even young fowls, when the hen gives the danger-cry, run away and try to hide themselves, like young partridges or pheasants, in order that their mother may take flight, of which she has lost the power. The musk-duck (_Cairina moschata_) in its native country often perches and roosts on trees,[5] and our domesticated musk-ducks, though such sluggish birds, “are fond of perching on the tops of barns, walls, etc., and, if allowed to spend the night in the hen-house, the female will generally go to roost by the side of the hens, but the drake is too heavy to mount thither with ease.”[6] We know that the dog, however well and regularly fed, often buries, like the fox, any superfluous food; and we see him turning round and round on a carpet, as if to trample down grass to form a bed; we see him on bare pavements scratching backwards as if to throw earth over his excrement, although, as I believe, this is never effected even where there is earth. In the delight with which lambs and kids crowd together and frisk on the smallest hillock, we see a vestige of their former alpine habits.
We have therefore good reason to believe that all the domestic races of the pigeon are descended either from some one or from several species which both roosted and built their nests on rocks, and were social in disposition. As only five or six wild species have these habits, and make any near approach in structure to the domesticated pigeon, I will enumerate them.
Firstly, the _Columba leuconota_ resembles certain domestic varieties in its plumage, with the one marked and never-failing difference of a white band which crosses the tail at some distance from the extremity. This species, moreover, inhabits the Himalaya, close to the limit of perpetual snow; and therefore, as Mr. Blyth has remarked, is not likely to have been the parent of our domestic breeds, which thrive in the hottest countries. Secondly, the _C.
rupestris,_ of Central Asia, which is intermediate[7] between the _C. leuconota_ and _livia_; but has nearly the same coloured tail as the former species. Thirdly, the _ Columba littoralis_ builds and roosts, according to Temminck, on rocks in the Malayan archipelago; it is white, excepting parts of the wing and the tip of the tail, which are black; its legs are livid-coloured, and this is a character not observed in any adult domestic pigeon; but I need not have mentioned this species or the closely-allied _C.
luctuosa,_ as they in fact belong to the genus Carpophaga.
Fourthly, _Columba guinea,_ which ranges from Guinea[8] to the Cape of Good Hope, and roosts either on trees or rocks, according to the nature of the country. This species belongs to the genus Strictoenas of Reichenbach, but is closely allied to Columba; it is to some extent coloured like certain domestic races, and has been said to be domesticated in Abyssinia; but Mr. Mansfield Parkyns, who collected the birds of that country and knows the species, informs me that this is a mistake. Moreover, the _C. guinea_ is characterised by the feathers of the neck having peculiar notched tips,—a character not observed in any domestic race. Fifthly, the _ Columba œnas_ of Europe, which roosts on trees, and builds its nest in holes, either in trees or the ground; this species, as far as external characters go, might be the parent of several domestic races; but, though it crosses readily with the true rock-pigeon, the offspring, as we shall presently see, are sterile hybrids, and of such sterility there is not a trace when the domestic races are intercrossed. It should also be observed that if we were to admit, against all probability, that any of the foregoing five or six species were the parents of some of our domestic pigeons, not the least light would be thrown on the chief differences between the eleven most strongly-marked races.
We now come to the best known rock-pigeon, the _Columba livia,_ which is often designated in Europe pre-eminently as the Rock-pigeon, and which naturalists believe to be the parent of all the domesticated breeds. This bird agrees in every essential character with the breeds which have been only slightly modified.
It differs from all other species in being of a slaty-blue colour, with two black bars on the wings, and with the croup (or loins) white. Occasionally birds are seen in Faroe and the Hebrides with the black bars replaced by two or three black spots; this form has been named by Brehm[9] _C. amaliæ,_ but this species has not been admitted as distinct by other ornithologists. Graba[10] even found a difference in the bars on the right and left wings of the same bird in Faroe. Another and rather more distinct form is either truly wild or has become feral on the cliffs of England and was doubtfully named by Mr. Blyth[11] as _C. affinis,_ but is now no longer considered by him as a distinct species. _C. affinis_ is rather smaller than the rock-pigeon of the Scottish islands, and has a very different appearance owing to the wing-coverts being chequered with black, with similar marks often extending over the back. The chequering consists of a large black spot on the two sides, but chiefly on the outer side, of each feather. The wing-bars in the true rock-pigeon and in the chequered variety are, in fact, due to similar though larger spots symmetrically crossing the secondary wing-feather and the larger coverts. Hence the chequering arises merely from an extension of these marks to other parts of the plumage. Chequered birds are not confined to the coasts of England; for they were found by Graba at Faroe; and W.
Thompson[12] says that at Islay fully half the wild rock-pigeons were chequered. Colonel King, of Hythe, stocked his dovecot with young wild birds which he himself procured from nests at the Orkney Islands; and several specimens, kindly sent to me by him, were all plainly chequered. As we thus see that chequered birds occur mingled with the true rock-pigeon at three distinct sites, namely, Faroe, the Orkney Islands, and Islay, no importance can be attached to this natural variation in the plumage.
Prince C. L. Bonaparte,[13] a great divider of species, enumerates, with a mark of interrogation, as distinct from _C. livia,_ the _C.
turricola_ of Italy, the _C. rupestris_ of Daouria, and the _C.
schimperi_ of Abyssinia; but these birds differ from _C. livia_ in characters of the most trifling value. In the British Museum there is a chequered pigeon, probably the _C. schimperi_ of Bonaparte, from Abyssinia. To these may be added the _C. gymnocyclus_ of G. R.
Gray from W. Africa, which is slightly more distinct, and has rather more naked skin round the eyes than the rock-pigeon; but from information given me by Dr. Daniell, it is doubtful whether this is a wild bird, for dovecot-pigeons (which I have examined) are kept on the coast of Guinea.
The wild rock-pigeon of India (_C. intermedia_ of Strickland) has been more generally accepted as a distinct species. It differs chiefly in the croup being blue instead of snow-white; but as Mr.
Blyth informs me, the tint varies, being sometimes albescent. When this form is domesticated chequered birds appear, just as occurs in Europe with the truly wild _C. livia._ Moreover we shall immediately have proof that the blue and white croup is a highly variable character; and Bechstein[14] asserts that with dovecot-pigeons in Germany this is the most variable of all the characters of the plumage. Hence it may be concluded that _C.
intermedia_ cannot be ranked as specifically distinct from _C.
livia._ In Madeira there is a rock-pigeon which a few ornithologists have suspected to be distinct from _C. livia._ I have examined numerous specimens collected by Mr. E. V. Harcourt and Mr. Mason. They are rather smaller than the rock- pigeon from the Shetland Islands, and their beaks are plainly thinner, but the thickness of the beak varied in the several specimens. In plumage there is remarkable diversity; some specimens are identical in every feather (I speak after actual comparison) with the rock-pigeon of the Shetland Islands; others are chequered, like _C. affinis_ from the cliffs of England, but generally to a greater degree, being almost black over the whole back; others are identical with the so-called _C. intermedia_ of India in the degree of blueness of the croup; whilst others have this part very pale or very dark blue, and are likewise chequered. So much variability raises a strong suspicion that these birds are domestic pigeons which have become feral.
From these facts it can hardly be doubted that _C. livia, affinis, intermedia,_ and the forms marked with an interrogation by Bonaparte ought all to be included under a single species. But it is quite immaterial whether or not they are thus ranked, and whether some one of these forms or all are the progenitors of the various domestic kinds, as far as any light can thus be thrown on the differences between the more strongly-marked races. That common dovecot-pigeons, which are kept in various parts of the world, are descended from one or from several of the above-mentioned wild varieties of _C. livia,_ no one who compares them will doubt. But before making a few remarks on dovecot-pigeons, it should be stated that the wild rock-pigeon has been found easy to tame in several countries. We have seen that Colonel King at Hythe stocked his dovecot more than twenty years ago with young wild birds taken at the Orkney Islands, and since then they have greatly multiplied.
The accurate Macgillivray[15] asserts that he completely tamed a wild rock-pigeon in the Hebrides; and several accounts are on records of these pigeons having bred in dovecots in the Shetland Islands. In India, as Captain Hutton informs me, the wild rock-pigeon is easily tamed, and breeds readily with the domestic kind; and Mr. Blyth[16] asserts that wild birds come frequently to the dovecots and mingle freely with their inhabitants. In the ancient ‘Ayeen Akbery’ it is written that, if a few wild pigeons be taken, “they are speedily joined by a thousand others of their kind.”
Dovecot-pigeons are those which are kept in dovecots in a semidomesticated state; for no special care is taken of them, and they procure their own food, except during the severest weather. In England, and, judging from MM. Boitard and Corbié’s work, in France, the common dovecot- pigeon exactly resembles the chequered variety of _C. livia;_ but I have seen dovecots brought from Yorkshire without any trace of chequering, like the wild rock-pigeon of the Shetland Islands. The chequered dovecots from the Orkney Islands, after having been domesticated by Colonel King for more than twenty years, differed slightly from each other in the darkness of their plumage and in the thickness of their beaks; the thinnest beak being rather thicker than the thickest one in the Madeira birds. In Germany, according to Bechstein, the common dovecot-pigeon is not chequered. In India they often become chequered, and sometimes pied with white; the croup also, as I am informed by Mr. Blyth, becomes nearly white. I have received from Sir. J. Brooke some dovecot-pigeons, which originally came from the S. Natunas Islands in the Malay Archipelago, and which had been crossed with the Singapore dovecots: they were small and the darkest variety was extremely like the dark chequered variety with a blue croup from Madeira; but the beak was not so thin, though decidedly thinner than in the rock- pigeon from the Shetland Islands. A dovecot-pigeon sent to me by Mr. Swinhoe from Foochow, in China, was likewise rather small, but differed in no other respect. I have also received through the kindness of Dr. Daniell, four living dovecot-pigeons from Sierra Leone,[17] these were fully as large as the Shetland rock-pigeon, with even bulkier bodies. In plumage some of them were identical with the Shetland rock pigeon, but with the metallic tints apparently rather more brilliant; others had a blue croup, and resembled the chequered variety of _C.
intermedia_ of India; and some were so much chequered as to be nearly black. In these four birds the beak differed slightly in length, but in all it was decidedly shorter, more massive, and stronger than in the wild rock-pigeon from the Shetland Islands, or in the English dovecot. When the beaks of these African pigeons were compared with the thinnest beaks of the wild Madeira specimens, the contrast was great; the former being fully one-third thicker in a vertical direction than the latter; so that any one at first would have felt inclined to rank these birds as specifically distinct; yet so perfectly graduated a series could be formed between the above-mentioned varieties, that it was obviously impossible to separate them.
To sum up: the wild _Columba livia,_ including under this name _C.
affinis, intermedia,_ and the other still more closely-affined geographical races, has a vast range from the southern coast of Norway and the Faroe Islands to the shores of the Mediterranean, to Madeira and the Canary Islands, to Abyssinia, India, and Japan. It varies greatly in plumage, being in many places chequered with black, and having either a white or blue croup or loins; it varies also slightly in the size of the beak and body. Dovecot-pigeons, which no one disputes are descended from one or more of the above wild forms, present a similar but greater range of variation in plumage, in the size of body, and in the length and thickness of the beak. There seems to be some relation between the croup being blue or white, and the temperature of the country inhabited by both wild and dovecot pigeons; for nearly all the dovecot-pigeons in the northern parts of Europe have a white croup, like that of the wild European rock-pigeon; and nearly all the dovecot-pigeons of India have a blue croup like that of the wild _C. intermedia_ of India. As in various countries the wild rock-pigeon has been found easy to tame, it seems extremely probable that the dovecot-pigeons throughout the world are the descendants of at least two and perhaps more wild stocks; but these, as we have just seen, cannot be ranked as specifically distinct.
With respect to the variation of _C. livia,_ we may without fear of contradiction go one step further. Those pigeon-fanciers who believe that all the chief races, such as Carriers, Pouters, Fantails, etc., are descended from distinct aboriginal stocks, yet admit that the so-called toy-pigeons, which differ from the rock-pigeon in little except colour, are descended from this bird. By toy-pigeons are meant such birds as Spots, Nuns, Helmets, Swallows, Priests, Monks, Porcelains, Swabians, Archangels, Breasts, Shields, and others in Europe, and many others in India. It would indeed be as puerile to suppose that all these birds are descended from so many distinct wild stocks as to suppose this to be the case with the many varieties of the gooseberry, heartsease, or dahlia. Yet these kinds all breed true, and many of them include sub-varieties which likewise transmit their character truly. They differ greatly from each other and from the rock-pigeon in plumage, slightly in size and proportions of body, in size of feet, and in the length and thickness of their beaks. They differ from each other in these respects more than do dovecot-pigeons.
Although we may safely admit that dovecot-pigeons, which vary slightly, and that toy- pigeons, which vary in a greater degree in accordance with their more highly-domesticated condition, are descended from _C.
livia,_ including under this name the above-enumerated wild geographical races; yet the question becomes far more difficult when we consider the eleven principal races, most of which have been profoundly modified. It can, however, be shown, by indirect evidence of a perfectly conclusive nature, that these principal races are not descended from so many wild stocks; and if this be once admitted, few will dispute that they are the descendants of _C. livia,_ which agrees with them so closely in habits and in most characters, which varies in a state of nature, and which has certainly undergone a considerable amount of variation, as in the toy-pigeons. We shall moreover presently see how eminently favourable circumstances have been for a great amount of modification in the more carefully tended breeds.
The reasons for concluding that the several principal races are not descended from so many aboriginal and unknown stocks may be grouped under the following six heads:— _Firstly._—If the eleven chief races have not arisen from the variation of some one species, together with its geographical races, they must be descended from several extremely distinct aboriginal species; for no amount of crossing between only six or seven wild forms could produce races so distinct as Pouters, Carriers, Runts, Fantails, Turbits, Short-faced Tumblers, Jacobins, and Trumpeters. How could crossing produce, for instance, a Pouter or a Fantail, unless the two supposed aboriginal parents possessed the remarkable characters of these breeds?
I am aware that some naturalists, following Pallas, believe that crossing gives a strong tendency to variation, independently of the characters inherited from either parent. They believe that it would be easier to raise a Pouter or Fantail pigeon from crossing two distinct species, neither of which possessed the characters of these races, than from any single species. I can find few facts in support of this doctrine, and believe in it only to a limited degree; but in a future chapter I shall have to recur to this subject. For our present purpose