122 WITH THE U. S. NATURALISTS 



in the neighborhood of hot springs and the natives 

 locate new springs by finding the nests of the birds. 

 But these, again, are rare cases. 



* ' So far as North American birds are concerned, 

 you can say that most of them with a few excep- 

 tions Uke Ruffed Grouse, Bob- White, Cardinal and 

 Carolina Wren, migrate northward for the nest- 

 ing-season and southward for the winter. It is a 

 part of the life-cycle of birds, as much so as the 

 round of seed, seedling, leaf, flower and seed 

 again, is the life-cycle of plants. 



''If you go on with your study of birds, Shan, 

 there is one thing you must remember from the 

 very start — that a large proportion of the birds 

 you see in summer are probably at the north of 

 their range and nesting, that many winter visitors 

 are probably at the south of their range and win- 

 tering, while the birds of spring and fall are prob- 

 ably species on their way to or from the great nest- 

 ing grounds of their kind. 



''The Bureau of Biological Survey has made a 

 special study of the migration of North American 

 birds. It is a matter of the greatest importance 

 to the United States government and to the people 

 of the United States. The Biological Survey un- 

 dertakes to aid in the drawing up of all laAvs re- 



