701,. XLVm, NO. 471 



THE 



AMERICAN 

 NATURALIST 



A MONTHLY JOURNAL 

 Devoted to the Advancement of the Biological Science! 1 

 Special Reference to the Factors of Evolution 



Swingle's Eiperim 



THE SCIENCE PRESS 

 JLANCASTER, PA. GARRISON, N. T. 



NEW YORK: SUB-STATION 84 



