358 THE DISTRIBUTION OF BIRD-LIFE. 



was left. The trees had been swept clean, as if by 

 some magical power, and the swarming billions had 

 disappeared. 



From whence had they come? Where had they 

 gone to? What was the reason of their coming and 

 their going? Alas! we know not but that they did 

 come, and did go, in the marvellous way we have 

 related that we can affirm. 



The study of bird life presents to our consideration 

 a field of research which is practically inexhaustible: 

 first, on account of the vast numbers of different species 

 and the great variations which birds exhibit in their 

 habits, etc. ; and next because of the difficulty in observing 

 them in a state of nature. The total number of species 

 among the birds known to ornithologists, according 

 to Mr. Seebohm, may be roughly set down at 10,000, * 

 which are distributed among five great families, f spread 

 over the whole surface of the globe, by land and sea. 

 From the summits of the highest mountains to the plain, 

 and from the equator to the poles, the bird is everywhere. 

 The ptarmigan or snow grouse (Lagopus Mutus] for 

 instance, is fairly numerous, as far as man has as yet 

 penetrated into the northern polar regions, where it 

 winters amid the eternal snows and finds a home 

 beneath its shelter. There can be little doubt that it 



* The Geographical Distribution of the Family of Charadriidce, by 

 Henry Seebohm, 1888, p. 4. 



\ Approximately as follows : 



Anseriformes .... 1000 



Cuculiformes .... 1900 



Passeriformes .... 5980 



Charadriformes ... noo 



Struthioformes ... 20 

 Total IO,OOO 

 See Jbt'd., by H. Seebohm, p. 4. 



