176 MIGRATION AND DISTRIBUTION 



pinned his faith to all the author's details or to all his 

 conclusions. 



As was the case with many other naturalists, he had 

 long been groping in the dark with regard to this 

 question, and Wallace's book immediately let in a flood 

 of light. 



With regard to the Ptarmigan question I think I can 

 tell you exactly how the mistake of admitting Lagopus 

 rupestris as a British bird originated. More than a 

 century since Edwards described and figured under the 

 name of " Rock Grouse " a Ptarmigan from Hudson's 

 Bay, which as the figure now shows must have been a 

 hen bird in the orange-yellow plumage of the breeding 

 season, and on this figure was founded the species known 

 in systems as Tetrao (or Lagopus) rupestris a name 

 which is therefore applicable to the smaller black-tailed 

 Ptarmigan of the northern parts of North America. 



The different plumages assumed by the Ptarmigan of 

 Europe were for a long time little known, and for at 

 least the first twenty years of the present century it was 

 generally (I do not say universally) assumed among 

 naturalists that this bird had but two states of plumage, 

 being white in winter and grey in summer, this last 

 assumption being, as we now know, partly an error, since 

 in the breeding season, i.e. at the beginning of summer, 

 the plumage of the hen is orange-yellow, while the grey 

 dress is put on later in the summer and may be more 

 correctly called the autumnal plumage. However, this 

 fact was not generally known to the naturalists of the 

 time who (with perhaps a few exceptions) believed that 

 the summer plumage of the European Ptarmigan was 

 grey and that of the American orange-yellow. 



Under this belief, some thirty years or more ago (I 

 cannot, in the absence of books, speak positively), a hen 

 Ptarmigan was sent from Scotland to (I think) Lord 

 Stanley in orange-yellow plumage, the ordinary plumage 

 of the breeding season, and as at that time it was con- 

 sidered that the American species only assumed a dress 



