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Show 242 FOWLS. CnAP. vn. degree the cross from the Hamburgh hen; the oth~r became a gorgeous bird, so much so that an acquaintance bad _It preRerve_d and stuffed simply from its beauty. When stalln~g about 1t closely resembled the wild Gallus banki'va, but w~th the r~d feathers rather J.arker. On close comparison one considerable chffcrence presented itself, namely, that the primar! and sec.ond~ry wino--feathers were edo-ecl with greenish-black, mstead of bemg edgeb d, as in G. banbk iva, with fulvous and re d tm· ts. mh .L e space, also, across the back, which boars dark-green feathers, waR broader, and the comb was blackish. In all other respects, oven in trifling d tails of plumage, there was the closest ~cco~·dance. Altogether it was a marvellous sight to compare this bu·d first with G. bankiva, and then with its father, the glossy greenblack Spanish code, and with its diminutive mother, th~ white Bilk hen. 'l'his case of reversion is the more extraordmary as tho Spanish breed has long been known to breed true, and no instance is on record of its throwing a single reel feather. The Silk ben likewise breeds true, and is believed to be ancient, for Aldrovaudi, before 1600, alludes probably to this breed, and describes it as covered with wool. It is so peculiar in many ·haracters that some writers have considered it as pecifically distinct; yet, as we now see, when crossed with the Spanish fowl, it yields offspring closely resembling the wild G. bankiva. Mr. Tegetmeier has been so kind as to repeat, at my request, the cross between a Spanish cock and Silk hen, and he obtained similar results; for he thus raised, besides a black hen, seven cocks, all of which were dark-bodied with more or less orangered hackles. In tho ensuing year he paired the black hen with one of her brothers, and raised throe young cocks, all coloured like their father, and a black hen mottled with white. The hens from the six above-described crosses showed hardly any tendency to revert to the mottled-brown plumage of the female G. banlciva: one hen, however, from the white Cochin, which was at first coal-black, became slightly brown or sooty. Several hens, which were for a long time snow-white, acquired as they grew old a few black feathers. A hen from the white Game, which was for a long time entirely black glossed with green, when two years old had some of the primary wing-feathers greyish-white, and a multitude of feathers over her body nar- CIIAP. VII. REVERSION AND ANALOGOUS VARIATION. 243 rowly and symmetrically tipped or laced with white. I had expected that some of the chickens whilst covered with down would have assumed the longitudinal stripes so general with gallinaceous birds; but this did not occur in a single instance. Two or three alone were reddish-brown about their heads. I was unfortunate in losing nearly all the white chickens from the first crosses ; so that l>lack prevailed with the grandchildren ; but they were much diversified in colour, some being sooty, others mottled, and one blackish chicken had its feathers oddly tipped aud barred with brown. I will here add a few miscellaneous facts connected with reversion, and with the law of analogous variation. This law implies, as stated in a previous chapter, that the varieties of one species frequently mock distinct but allied species; and this fact is explained, according to the views which I maintain, on the principle of allied species having descended from one primitive form. The white Silk fowl with black skin and bones degenerates, as has been observed by Mr. Hewitt and Mr. H. Orton, in our climate; that is, it reverts to the ordinary colour of the common fowl in its skin and bones, due care having been taken to prevent any cross. In Germany 30 a distinct breed with black bones, and with black, not silky plumage, has likewise been observed to degenerate. Mr. Tegetmeier informs me that, when distinct breeds are crossed, fowls are frequently produced with their feathers marked or pencilled by narrow transverse lines of a darker colour. This may be in part explained by direct reversion to the parent-form, the Bankiva hen; for this bird has all its upper plumage finely mottled with dark and rufous brown, with the mottling partially and obscurely arranged in transverse lines. But the tendency to pencilling is probably much strengthened by the law of analogous variation, for the hens of some other species of Gallus are more plainly pencilled, and the hens of many gallinaceous birds belonging to other genera, as the partridge, have pencilled feathers. Mr. Tegetmeier has so 'Die Hiihner und Pfauenzucht.' Ulrn, 1827, s. 17. For Mr. Hewitt's statement with respect to the white Silk fowl, see the 'Poultry Book,' by W. B. Tcgetmeier, 186G, p. 222. I am indebted to Mr. Orton for a letter on the same subject. R 2 |