THE BED GROUSE. 77 



possible to suppose that each bird could select the surround- 

 ings suitable to its own plumage. Nor is the principal 

 variation in the back — although that is the portion which 

 requires protective assimilation — but in the underparts, 

 which are concealed when the birds squat ; and these varia- 

 tions are therefore considered to be instances of individual 

 difference or polymorphism. 



Some birds bred on high ground shew a tendency to white 

 underparts in winter, and, although rare, instances are not 

 unknown of a change similar to that observed in the Willow- 

 Grouse. Mr. John Marshall, of Belmont, Taunton, has two 

 birds said to have been shot in Perthshire, in which the 

 quill-feathers are white with black shafts ; the tail black, 

 tipped with white ; the tail-coverts pure white ; and the 

 body white, sprinkled with dark feathers about the head and 

 neck. A male specimen in the collection formed by Messrs. 

 Salvin and Godman, and now in the British Museum, 

 obtained on the Island of Lewis in October, has a consider- 

 able amount of white on the throat. Varieties of a greyish- 

 buff are sometimes obtained, and on one of these, purchased 

 from a dealer, the late Mr. G. R. Gray conferred the name 

 of Lagopus persicus, under the impression that it came 

 from some place in Persia. This specimen is figured in Gray 

 and Mitchell's * Genera of Birds,' vol. iii. p. 517, pi. cxxxiii., 

 and in Mr. D. G. Elliott's Monograph of the Tetraonidce, but 

 there can scarcely be a doubt that the locality was assigned 

 in error. A similar variety has been obtained in co. Mayo 

 (A. G. More, Zool. 1882, p. 147) ; and examples of a cream 

 colour have been recorded by Selby (111. Brit. Orn. i. p. 249) 

 from the moors of Blanchland in the county of Durham, 

 but from the anxiety of sportsmen to procure specimens, 

 these birds were not allowed to increase. 



Red Grouse also vary much in weight in different districts 

 and according to the time of year, being at their best both 

 as regard weight and plumage in November. A cock Grouse 

 generally weighs about 1^ and a hen about 1|- lbs., but 

 many birds are on record up to 2 lbs. The weight of the 

 heaviest birds shot between 1874-1881 on Rousay in the 



