VOL. L, NO. S99 



NOVEMBER. 1816 



THE 



AMERICAN 

 NATURALIST 



A MONTHLY JOURNAL 

 Devoted to the Advancement of the Biological Sciences with 

 Special Reference to the Factors of Evolntion 



The Evolutionary Significance of the Osmotic Pressure of the Blood. 



Shorter Articles and Discust 



THE SCIENCE PRESS 

 LANCASTER, PA. GARRISON, N. Y. 



NEW YORK: SUB-STATION 84 



