OCR Text |
Show 414 DR. EINAR LONNBERG ON [Mar. 1, The Blackcock inheritance, however, is conspicuous in the black feathers or black bases of white feathers. From this analysis it is apparent that the Riporre in winter plumage is unable to produce the buff pigment which is found in the immature Blackcock, so that therefore this coloration is substituted by white, often in an exaggerated way. It is also obvious that areas that in the Blackcock are mottled have a greater tendency to become white in the Riporre than spotted black. The feathers of the Blackcock which are more or less pale-edged become in the Riporre more broadly white-edged or retain only a black base. In the areas in the Blackcock which are quite black or glossy black, the same coloration is most dominant in the Riporre as well. The tarsi and toes of these specimens are white with long feathers, especially in the specimen which has assumed full winter garb. The claws are very large and coloured as in the Willow- Grouse, that is, paler than in the Blackcock. The length of the middle claw is in one specimen 22 mm.; in the other, which was shot earlier, 20 m m . The claws are, however, compared with their length not so broad as in the Willow-Grouse, and distinctly oblique as in the Blackcock. From the latter is also inherited the toothed comb underneath the toes. The feet are thus quite intermediate in structure. The lengths of the wings are respectively 234 and 237 m m. This measurement thus agrees with the smaller and medium-sized specimens which Collett has measured. A third male specimen of Riporre kept in the Upsala Museum, and obtained from the province of Vesterbotten, is a good deal darker than those just described. But its coloration adheres to the same systematic pattern. The neck, except in front, is quite black, with narrow white edges to the feathers. The fore-neck looks white, but the concealed parts of the feathers are black. The upper breast is wholly glossy black*. The metallic lustre is not, however, blue as in the Blackcock, but rather purple as in the Rachelhane (hybrid between Oaper-caillie 2 and Blackcock); and this is of interest, because it indicates that the structure of the glossy feathers of the Blackcock seems to be influenced in a similar way through hybridisation with Willow-Grouse as with Capercaillie t. The flanks, wing-coverts, wings, &c. are also darker in this specimen, the front of the tarsi is mixed with grey, and the claws are darker than in the specimens described above. But in spite of this the general arrangement of the coloration is the same, and this seems to indicate that there is only one kind of Riporre-hybrids produced in the same way by a Grey-hen mated with a male * It is probable that this specimen is older than the others. It is in very fine plumage, and somewhat larger in size, the wing measuring 245 m m . t The purple lustre of the Rachelhane cannot therefore be interpreted as having originated by a mixing of the structures causing the green lustre in the Capercaillie and those causing the blue in the Blackcock. |