OF THE BEITISH ISLANDS. 43 



the same colour. They measure on an average 2"2 inches in length by 1"6 inch 

 in breadth. One brood only is reared in the year, and incubation lasts from 

 twenty-six to twenty-eight days. 



Diagnostic characters — Tetrao, with the tail nearly square, and the 

 wing more than 12 inches in length. Length, 35 inches (male) ; 25 inches 

 (female). Hybrids are pretty frequent in a wild state between the Black Cock 

 and the female Capercaillie, the latter being much given to wandering from their 

 usual haunts and pairing with Black Game during these peregrinations. Hybrids 

 have also been known between the female Capercaillie and the male Willow 

 Grouse, and the species is said occasionally to cross with the Pheasant. 



