26 Proceedings of the Royal Physical Society. 



of neck and breast with broad band of dark glossy green, 

 showing reddish purple reflections when looked at laterally, 

 which is also to be observed in the male capercailzie (this 

 reddish purple colour of breast seems entirely to take the 

 place of the green, in the hybrid between this bird and the 

 blackcock, — the Tetrao medius as it has been named). At 

 lower part of breast, the green colour passes into blackish 

 brown, mottled slightly with grey at the sides ; below, and 

 abdomen, white or nearly so, with numerous spots of black, 

 the dark feathers being broadly tipped with white ; lower 

 tail coverts black, tipped with white ; thighs white, legs and 

 feet dark grey, the toes being dark brown, with the claws 

 nearly black. The colours of the plumage, however, are not 

 quite so brilliant as in the male. 



The bird was shot on the 2d November, near Dunkeld, 

 on the property of Hugh Bruce, Esq. Mr Sanderson, bird- 

 stufTer, George Street, has sent along with it adult speci- 

 mens of the male and female for comparison, and its re- 

 semblance to the male is very striking. Mr James Keddie, 

 Mr Sanderson's assistant, called my attention to the finer 

 texture of the accessory plumes of the feathers, in all female 

 birds showing the plumage of the male. Yarrell described 

 this change to the male plumage as having been observed in 

 various species of birds, but apparently had seen no instance 

 in the capercailzie ; he says, M. Nilsson, in his " Illustra- 

 tions of the Fauna of Scandinavia," has figured "a female of 

 the wood-grouse in the plumage of the male, which he truly 

 calls a barren female/' and he copies the drawing in his 

 " British Birds/' The bird now exhibited closely resembles 

 that figured by Yarrell, with the exception that its ter- 

 tiaries and scapulars seem to be more tipped with white, and, 

 so far, slightly resembles the plumage of the adult female. 



In 1857 I exhibited to the Society various specimens of 

 the pheasant, showing this curious assumption of the male 

 plumage.* The general opinion is, that a change of this 

 kind occurs along with an atrophied or changed state of the 

 ovaries, the result of age it may be, or of disease. In this 



* See Pro-c., vol. ii. p. 58. 



