418 Mr. H. E. Dresser's Notes on 



All the above species are certainly descended from four 

 different parent forms, and have spread into the localities in- 

 habited by the four following species, viz. Anser skornia- 

 kovi {A. indicus), Bernicla jncta, Bernicla ruficolUs, and Ber- 

 nicla torquata, which do not subdivide into different forms ; 

 but the former groups are still undergoing the struggle for 

 existence, the balance being on the side of A. seyetum and A. 

 albifrons. I also observed that "svhen on migration in the 

 Ural, A. albifrons and A. minutus existed together very well, 

 but A. medius, the intermediate form between these two 

 species, was not so numerous. All these facts are proofs in 

 favour of the Darwinian theory, of which the Geese give many 

 interesting illustrations.^' 



359. Anser segetum (Gm.); Severtzoff, p. 70. 

 Horizontal range. Occurs on passage in districts 1., II., and 



III., and winters in the last. 



Vertical range. Occurs on passage in districts 1 and "Z, and 

 winters in district 2. 



360. Anser obscurus, Brehm ; Severtzoff, p. 70. 

 Horizontal range. Is rare in winter in district III. 

 Vertical range. Occurs in winter in district 2. 



361. Anser cinereus, Meyer; Severtzoff, p. 70. 

 Horizontal range. Breeds in all four districts, and winters 



in district III. 



Vertical range. Breeds in districts 1, 2, 3, and 4, and win- 

 ters in district 2. 



362. Anser albifrons, Bechst. ; Severtzoff, p. 70. 

 Horizontal range. Occurs rarely on passage and in winter in 



district III. 



Vertical range. Occurs on passage in district 1, and rarely 

 in winter in district 2. 



363. Anser cygnoides (L.) ; Severtzoff, p. 70. 

 Horizontal range. Possibly breeds in district I. 

 Vertical range. Possibly breeds in district 2. 



364. Bernicla ruficollis (Pall.). 

 Anser ruficollis, Severtzoff, p. 70. 



