CASES OF ADAPTATION 155 



migration lasted more than a month. A^ery little migration was 

 observable till the last week in May, but during the next fortnight 

 the migration was prodigious. In additions to enormous numbers 

 of passerine birds, countless flocks of geese, swans, and ducks ar- 

 rived, together with a great many gulls, terns, and birds of prey. 

 During the next fortnight, from the 5th to the 19th of June, fresh 

 species of passerine birds continued to arrive, and the main migra- 

 tion of the great plover family took place." 



One of the objects of Mr. Seebohm's journey to the Arctic 

 regions was to obtain authentic eggs and nests of the grey 

 plover. He found several, after long search. They were all 

 situated in depressions on a slight ridge among black bog-lakes, 

 and each had three or four eggs. The charming little i)icture 

 on the next page shows both nest, eggs, and young birds. 



In order to ascertain approximately how many species of 

 birds visit the Arctic regions in the summer breeding season, 

 I have made rough lists of all those enumerated by Mr. 

 Seebohm in his two books, Siberia in Europe and Siberia in 

 Asia, and find that they amount to 160 species. This is very 

 nearly equal to the whole number of resident and migratory 

 birds which breed in our own country (about ISO) ; but they 

 cannot be more than a portion of the species that actually 

 migrate to the Arctic lands, as they were the result of two 

 visits only of about a couple of months each, and only two very 

 limited areas were explored. My friend, Mr. II. E. Dresser, 

 who also knows these regions personally and has made a special 

 study of their birds, has been so good as to make an enumera- 

 tion of all the birds known to breed in the Arctic regions 

 of Europe and Asia, and he finds it to be land birds 81) species, 

 waders and aquatics 84 species, equal to 173 in alL Consider- 

 ing how vast is the extent of the country, and how few ornithol- 

 ogists visit it, we may put the total number at at least ISO, 

 and possibly even 200 species. 



The great accumulation of bird-life is, however, vividly pic- 

 tured by Mr. Seebohm, and it is clear from all that he says — 

 as well as bv what he does not sav — that the vast hordes of 



