CASES OF ADAPTATION 145 



good as to make an enumeration of all the birds known to 

 breed in the Arctic regions of Europe and Asia, and he finds 

 it to be land birds 89 species, waders and aquatics 84 

 species, equal to 173 in all. Considering how vast is the 

 extent of the country, and how few ornithologists visit it, 

 we may put the total number at at least 180, and possibly 

 even 200 species. 



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

 pictured by Mr. Seebohm, and it is clear from all that he 

 says — as well as by what he does not say — that the vast 

 hordes of mosquitoes must be the chief support of the 

 innumerable millions of young birds which have to be fed 

 here, both passerine and wading birds. Of the former, 

 more than eighty species are named, including seven 

 buntings, four tits, two grosbeaks, six pipits, eleven 

 warblers, five wagtails, two sparrows, three woodpeckers, 

 the beautiful waxwing, and a host of others, many of which 

 are among our common birds. What a delight to them all 

 must be this rush northward into a land of perpetual 

 daylight, swarming with the most nutritious food, fruits and 

 berries for the parents, inexhaustible clouds of mosquitoes — 

 which Mr. Seebohm tells us are an especially large kind 

 with bodies a third of an inch long — and the equal myriads 

 of their larvae in every little pond or water-hole, as well as 

 quantities of larger worms and larvae. The extreme dis- 

 comforts as well as the cost of a journey to these far 

 northern lands are so great that very few bird- or insect- 

 collectors visit them, and it is not easy to obtain direct 

 and accurate observations as to the actual part played 

 by the myriad swarms of mosquitoes in attracting birds from 

 almost every part of the northern hemisphere to go and breed 

 there. Mr. H. E. Dresser, who has made a special study 

 of Palaearctic birds and their eggs, has, however, obtained for 

 me some very interesting information. He writes : 



"Colonel Feilden tells me that the young of the knot are fed 

 chiefly on the larvae of mosquitoes." 



He has also sent me a copy of the following interesting 

 letter from an American ornithological correspondent, Mr. 

 E. T. Seton 



L 



