J 



VOL. XLIX, KO. 680 



APRIL, 1915 



THE 



AMERICAN 

 NATURALIST 



A MONTHLY JOURNAL 

 Devoted to the Advancement of the Biological Sciencei with 

 Special Reference to the Factors of Evolution 



THE SCIENCE PRESS 

 JUANGASTER, PA. GARRISON, H. f . 



NEW YORK: SUB-STATION 84 



