VOL. I, NO. 593 



MAY, 1916 



THE 



AMERICAN 

 NATURALIST 



A MONTHLY JOURNAL 

 Devoted to the Advancement of the Biological Sciencei with 

 Special Eeference to the Factors of Evolution 



» Protozoan Life Cycle. Professor Gary N. Calkins - 86T 

 Ml. The late Professor E. A. MiNCHnr - - - -2" 



i Kernels. T. K. Wolfi 



THE SCIENCE PEESS 

 LANCASTER, PA. GAEEISON, N. Y. 



NEW YORK: SUB-STATION 84 



