The New British Sand-Grouse. 205 



from here to Tartary ? Again, whatever the influence might 

 be, how special must have been its operation not to have acted 

 upon other birds peculiar to the same country, for no other such 

 visits have been recorded. The present summer has been re- 

 markable rather for the scarcity of the usual summer visitors; 

 the most unusual wanderers hither, besides the Syrrhaptes, are 

 the Demoiselle crane, of North Africa, and some Canada geese ; 

 which latter, if the examples observed be not escaped birds, 

 certainly came from an exactly opposite direction to the Syrrhap- 

 tes. On looking over the pages of the Zoologist for 1859, I find 

 that the only unusual eastern bird which was observed during 

 that year, was a specimen of the little bustard ( Otis tetrax) , shot 

 near Oxford, in the beginning of October ; but specimens of this 

 species had been shot in England in several previous years, 

 though never in the breeding season ; and although it inhabits 

 Tartary, like the Syrrhaptes, it by no means follows that any of 

 these wanderers came from thence, for the species inhabits not 

 only North Africa also, but is found as well in several parts of 

 Southern Europe. One fact, however, connected with this species 

 lets in a faint glimmer of light upon this obscure subject. M. 

 Menetries states that these birds are very common at the foot 

 of Mount Caucasus, and particularly so towards the shores of 

 the Caspian sea ; and near Baiku, he saw in December, immense 

 flocks of these birds going in the direction from east to west. 

 This looks like a migration in the direction of longitude, as 

 surmised, in the case of some other birds, by Dr. A. L. Adams, 

 a most observant Indian ornithologist. Now migration in the 

 direction of longitude will differ from migration in the direction 

 of latitude in this important particular, that the difference in 

 temperature will, in the former, be so slight as to be scarcely 

 appreciable, while in the latter it will rise or fall most rapidly ; 

 so that a migration from Tartary, in nearly the same parallel, 

 will not meet that check, in respect of temperature, which 

 would in a northern or southern direction at least exercise 

 some influence upon its extent. Applying these considerations 

 to the case of the Syrrhaptes, we yet cannot fail to wonder why 

 their near allies, and our nearer neighbours, the European sand- 

 grouse, have not moved westward too, but, on the contrary, 

 have literally allowed the Syrrhaptes to come over their heads ! 

 Strange too that these birds should have come in the breeding 

 season, and that so far advanced ! 



Having now related sufficient to show the extreme interest 

 attaching to the Syrrhaptes in a geographical point of view, it 

 will be desirable to describe its structure and relationship a 

 little more fully, to show that its physiological character are 

 quite as remarkable. 



The sand-grouse are strictly confined to the Old World, and 



