HYBRID GROUSE. 



581 



love-songs every day from the same tree, and these birds re- 

 gularly return to their roosting-places in the evening, and in 

 the morning conduct themselves just like the Capercaillies. 

 Others, on the contrary, repair every morning to a certain 

 drumming-place of the Blackcock, whether it be situated on 

 a heath, a clearing, a glade, or a moor ; there they drum in 

 company with their smaller relatives, fight with them gene- 

 rally very valiantly, and haunt the neighbourhood of the 

 spot throughout the day, especially in the evening, coiiducting 

 themselves in every respect just like the Blackcock. 



Their plumage, too, however much it may, as a whole, look 

 like that of a special type, must, when viewed in detail, be 

 recognized as a blending of that of both parents, for the feathers 

 of the Capercaillie and the Blackcock are reproduced un- 

 changed in the plumage of the Hybrid. Only in the ruddy 

 sheen of the breast does it differ materially from the green of 

 the former and the blue of the latter ; and it is just this remark- 

 able reddish play of colour which is a constant characteristic 

 of all Hybrid Cocks. The beak and the feet, too, as well as the 

 whole appearance of the bird, undoubtedly form, both in size 

 and shape, a true intermediate stage between the Capercaillie 

 and the Blackgame. 



It is, however, the study of the skeleton that, above all, 

 stamps the Tetrao medius as a cross; and I here give the 

 varying numbers of the vertebrae in three of these birds which 

 I got in Bohemia : 



