EDITOR'S INTRODUCTION xvii 



more ; or they must be aimed at the general ecological 

 status of the species, making it more difficult for it to live 

 and reproduce, as has in another sphere been accomplished 

 by drainage and cultivation v^ith regard to the malarial 

 mosquito. 



I recommend Mr. Elton's book to biologists as a valuable 

 and original contribution to pure science, and as a fresh 

 foundation for applied zoology. 



JULIAN S. HUXLEY. 



February, 1927. 



