carrying on these investigations we touched at a number of places on the 

 mainland of Alaska, and while cruising along the Aleutian chain of 

 islands we visited most of those which are inhabited. 



While the study of the birds of these regions was only an incidental 

 part of my work, nevertheless I had opportunity to make considerable 

 collections at Alexandrovsks and Saldovoi in Cook's Inlet, at Nuchek in 

 Prince William Sound, on Kadiak Island, TJnalaska, Amaknak, Atka and 

 Attu islands, also upon Bering Island of the Commander group. 

 Among these is a series of ptarmigan that is of much interest. 



The species represented are the following : Willow Ptarmigan (Lagopus 

 lagopus) and Rock Ptarmigan (L. rupestris) from Kadiak Island, Nelson's 

 Ptarmigan (L. rupestris nelsoni) from Amaknak and Unalaska islands, 

 Turner's Ptarmigan (L. rupestris atkensis) from Atka Island, and an undes- 

 cribed species from the island of Attu, the most westerly of the Aleutian 

 chain. 



The two species from Kadiak Island were collected April loand 14, and 

 are interesting as showing the plumage at that season. The Willow 

 Ptarmigan ranges near the bases of the mountains and amoD.ir the sparse 

 willow growth of the lower portions of the island. At the time of our 

 visit the snow had melted from considerable areas frequented by this 

 species, while higher up the mountains, where we found the Rock 

 Ptarmigan, and where there is little or no woody vegetation, the snow 

 covering everything completely. 



The principle of adaptation to environment was clearly illustrated by 

 these two species. The one whose range was in the region still covered 

 entirely with snow had not yet begun to change from winter to summer 

 plumage, not one of the sixty odd specimens collected showing a single 

 brown feather ; the plumage of every one was a solid white. Not so, 

 however, with the Willow Ptarmigan. Their plumage had already begun 

 to change gradually with the slowly melting snow, and in most cases the 

 head and neck had almost completely changed to the summer brown, 

 while brown feathers were scattered here and there through the rest of 

 the plumage. 



It is easy to see that it is greatly to the advantage of each of these 

 species to change from winter to summer plumage synchronously with 

 the melting snows ; too rapid or premature change as well as change too 

 long delayed would defeat the object of protective coloraiion. 



Specimens of Nelson's Ptarmigan were obtained May 10 and 20, and 



