£i.60 per Year (Foreign). 



AMERICAN 

 NATURALIST 



A MONTHLY JOURNAL 



DEVOTED TO THE NATURAL SCIENCES 



IN THEIR WIDEST SENSE. 



Managing editors: 





31. XXVI. APRIL, 1892. 



No. 304 



CON'T 



Plant Physiology as at 

 Germany and England. 



(Continued.) EL Gregory. 279 



(Continued.) (Illustrated.) H. J. Webber. 287 

 of the National Academy of Sciences. . . .319 



E N T S . 



Mineralogy anH Petrography.— -Perr 



Positi, . of OrtheloM i - 



^ T LlTERATCRE --Some Recent Zoological Text- 

 books— Stam-las Meuru-r\ ■• f.es Methodes de 

 Synthese eu Mineralo^ie - The Worms of 

 Bonn's Thier-Reichs. " 324 





PHILADELP 



BIDDER < 



518 and 520 W 



& KELLY, 



iNOR STREET 





