Migration in the Mississippi Valley 337 



coasts of Burma and the Bay of Bengal in winter, but are 

 neither of them found to the southward along the shores 

 of the Malayan Peninsula. As for other suggested migra- 

 tion-routes, the evidence is at present purely conjectural, 

 and no statistics are yet possible. 



In North America there are also lines of migration- 

 flight, which are apparently well defined, one on the 

 Atlantic side, another along the Pacific coast, and a third 

 route along the Great Mississippi Valley. We find certain 

 species, especially Wading-birds, which frequent the 

 western coast of North America and migrate southwards 

 to the South American continent, always following the 

 western coast-line. Similarly certain species follow the 

 eastern coast route, but while some Passerine birds winter 

 in Central America, others do not follow the continental 

 line, but pass by the West Indian Islands and those of the 

 Bay of Honduras to the Northern coast of South America 

 and Brazil. 



The waves of migration which pass up the Mississippi 

 Valley have been checked by Dr. W. W. Cooke and a 

 number of observers, and the facts elicited are of the 

 highest importance, though they seem to have been over- 

 looked by recent writers on migration in this country. 

 In the years 1885 and 1886 Dr. Cooke, with the aid of a 

 number of other skilled observers, traced the migration 

 wave in the Mississippi Valley, and among the facts which 

 they observed was the particularly interesting one that 

 sudden cold not only checked the birds on their northern 

 flight, but that several species not only arrested their 

 progress, but even went back for the time. I give a short 

 quotation from Dr. Cooke's work to show the careful way 

 in which the records were kept and the conclusions 

 tabulated. This is the method which will have to be 

 everywhere followed if we are to understand what migra- 

 tion really means, and the only manner in which we can 



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