340 THE ZOOLOGIST. 



distinct from the same stages of A. albifrons ; and, as I have 

 before said, I can find no proper description of these stages, it 

 will be necessary in proving my case to publish a full but brief 

 description of these and the other leading features in my two 

 series of birds. I ought perhaps to say that the stock of books 

 available to me here is limited — I particularly lack American 

 works — and I should like it to be understood that I do not 

 positively assert that no proper description of these stages of 

 plumage has ever been published, but that I cannot find any. 



Anser gambeli. — Immature male, first plumage. Shot Co. Gal- 

 way, end of November, 1895. 



The immature plumage of any of the Wild Geese may always 

 be known by the small size of the feathers clothing the body ; 

 in first plumage the feathers are not half the size of those of an 

 adult bird. The feathers gradually increase in size as the bird 

 advances towards January and February. With the growth of 

 these feathers there is a change in the colouring matter, inde- 

 pendently of a moult. But when the black feathers begin to 

 appear on the breast, they are frequently, but not always, newly 

 moulted feathers. I have plenty of evidence showing the black 

 colouring matter being transmitted into drab feathers; indeed, 

 this deposition of the black pigment goes on slowly until the 

 whole under parts become jet-black. In the case of the immature 

 birds, of A. gambeli especially, advancing towards maturity, it is 

 first a gradual extraction of the dark colouring matter from the 

 feathers, eventually leaving the breast and under parts almost if 

 not quite white ; then the full drab colour of the adult bird 

 gradually deepens, and with it the black colour begins to appear. 

 As I have before said, these changes are accompanied by a moult, 

 and probably by the time the breeding period comes round the 

 whole body has been clothed in new feathers. 



I have given these general facts here, as it will be necessary to 

 keep them in view in connection with the following descriptions. 



The general appearance of this bird's first plumage is a very 

 dark blackish brown ; but compare this first plumage with the 

 black-breasted breeding stage, and it is easy to see that this 

 young bird belongs to a parent who finds black under parts 

 useful to it as a protective colouring during the breeding season. 



