414 DR. EINAR LONNBERG ON [Mar. 1, 



The Blackcock inheritance, however, is conspicuous in the black 

 feathei-s or black bases of white feathers. From this analysis it 

 is apparent that the Ripoi're in winter plumage is unable to 

 produce the buff pigment which is found in the immature Black- 

 cock, so that therefore this coloration is svibstituted by white, 

 often in an exaggerated way. It is also obvious that ai-eas 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 ai-e more or less pale-edged become in the 

 Riporre more broadly white-edged oi- retain only a black base. 

 In the areas in the Blackcock which are quite black or glossy 

 black, the same coloi-ation 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 earliei', 20 mm. 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 mm. 

 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 $ and Blackcock) ; and this is of intei-est, because it 

 indicates that the structure of the glossy feathers of the Black- 

 cock seems to be influenced in a similar way through hybridisa- 

 tion 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-hyhrids 

 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 mm. 



t The purple lustre of the Rachelhane cannot therefore be interpreted as having 

 originated bj' a mixing of the structures causing the green lustre in the Capercaillie 

 and those causing the blue in the Blackcock. 



