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Show 158 DOMESTIC PIGEONS. CHAP. V· and short-faced Tumblers. The remaining domestic forms ~ight have been included in the same genus with the wild rock-pigeon. Individual Variability; Variations of a remarkable nature. The differences which we have as yet consid~red are ch~racteristic of distinct breeds ; but there are other differences, e1ther confined to individual birds, or often observed in certain breeds but not characteristic of them. 'rhese individual differences arc of importance, as they might in most cases be secure~ ~nd accumulated by man's power of selection ; and thus an ex1st~ng br ed miaht be greatly modified or a new one formed. Fanciers notice and select only those slight differences which are exterually visible; but the whole organisati~n is so tie~ together by correlation of growth, that a change m one part IS fr~que~tly accompanied by other changes. For our purpose, mod1ficat1~ns of all kinds are equally important, and, if affecting a part wlnch does not commonly vary, are of more importance than a modification in some conspicuous part. At the present day any visible deviation of character in a well-established bi·eed is rejected as a blemish ; but it by no means follows that at an early period, before well-marked breeds had been formed, such deviations would have been rojoctocl; on the contrary, they would have been eagerly preserved as presenting a novelty, and would then have been Slowly augmented, as we shall hereafter more clearly soc, by the process of unconscious selection. I have made numerous measmements of the various parts ot the body in tho several breeds, and have hardly ever found tbem quito tho same in birds of tho same breed,-the differences being greater than we commonll meet with in wild species. To boo-in with tho primary feathers of the wing and ~'til; but I may fu·st mention, ~ some readers may not be aware of tho fact, that the number of tho primary wing and tail feathers in wild birds is generally constant, and characterises, not only whole genera, but oven whole families. When tho tail-feathers are unusually numerous, as for instance in tho swan, they arc apt to be variable in number; but this docs not apply to tho several species a11.d genera of tho Columbidro, which never (as far as I can hear) have less thn.n twelve or more than sixteen tail-feathers; and these numbers characterise, with rare exception, whole sub-families.27 The wild rock-pigeon has twelve tail-feathers. With Fan- • 27 • Coup-<l'roil bur l'Ol'llre llcs Pig om;,' par C. L. Bonaparte r,Uomptrs llendus\ 1854-!i5. 1\Ir. Blyth, in 'AnnnJs of Nut. Jiist.,' vol. xix., 1847, CHAI'. V. INDIVIDUAL VARIABILITY. tails, as wo havo seen, the number varies from fourteen to forty-two. In two young birds in tho same nest I counted twenty-two and twenty-seven feathers. Pouters are very liable to havo additional taH-foathors, and I have soon on sovoml occasions fourteen or fifteen in my own birds. Mr. Bult had a specimen, examined by Mr. Yarrell, with seventeen tail-feathers. I had a Nun with thirteen, and another with fourteen tail-feathers; and in a IIolmet, a breed barely distinguishable from tho Nun, I have counted fifteen, and bavo heard of other such instances. On tho other hand, Mr. Brent possessed a Dragon, which during its whole life nev01:had more than ton tail-feathers; and one of my Dragons, descended from Mr. Brent's, bad only cloven. I have soon a Baldhoad-Tumblor with only ten; and Mr. Brent had an Air-Tumbler with tho same number, but another with fomteen tail-fealhers. Two of these latter Tumblers, bred by Mr. Brent, wore romarkablo,-ono from having tho two central tail-feathers a little divergent, and the other from having tho two outer feathers longer by throeeighths of an inch than the others; so that in both cases the tail exhibited a tendency, but in diflerent ways, to become forked. Anu this shows us how a swallow-tailed breed, like that described by Bechstein, might have been formed by careful selection. With respect to the primary wing-feathers, tho number in tho Columhidro, as far as I can find out, is always nino or ton. In tho rock-pigeon it is ton; but I have soon no less than eight short-faced Tumblers with only nino primaries, and the occmrence of this number has been noticed by fanciers, owing to ten flight-feathers of a white colour being one of tho points in Short-faced Baldhead-Tumblors. Mr. Brent, however, had an AirTumbler (not short-faced) which had in both wings cloven primaries. Mr. Corker, tho eminent breeder of prize Carriers, assures me that some of lJis birds had eleven primaries in both wings. I have seen eleven in one wing in two Pouters. I have been assmed by throe fanciers that they hn.ve seen twelve in Scanderoons; but as Neumeister assorts that in tho allied Florence Runt tho middle flight-feather is often double, tho number twelve may have boon caused by two of tho ten primaries having each two shafts to a single feather. The secondary wing-feathers aro difficult to count, but tho number seems to vary from twelve to fifteen. Tho length of the wing and tail relatively to the body, and of the wings to the tail, certainly varies; I have especially noticed this in Jacobins. In Mr. Bult's magnificent collection of Pouters, the wings and tail varied greatly in length; and wore sometimes so much elongated that the birds could hardly play upright. In tho relative length of tho few first primaries I have observed only a slight degree of variability. Mr. Brent informs roo that he has observed tho shape of the first feather to vary very slightly. But tho variation in these latter points is extremely slight compared with what may often be observed in tho natuml species of tho Columbidro. In tho beak I havo observed very considerable differences in birds of the p. 41, mclltions, as a very singular fact, " that of tho two species of Ectopil:!tes, whielt n.ro nearly nllicd lo ench other, one should lmve fourteen lail-ti.'ath<:rs, while tile other, the passenger pigeon of North America, should possess but tho usual number-twelve." |