214 The American Naturalist. [March, 



This implication of narrowness and specialization is, in the 

 writer's opinion, extremely unjust and lacking foundation in 

 truth. The fact that he chooses to devote special attention to 

 the mechanical problems connected with the subject of growth, 

 by no means proves his unwillingness or inability to cope with 

 all the questions connected with the subject, those referring to 

 plant nutrition as well as those of growth. It is, however, 

 unquestionably true that the habit of reasoning induced by 

 studies of this nature is such as to lead to a different treat- 

 ment of the questions of plant nutrition from that adopted by 

 most of his cotemporaries. 



For example, in all those questions included in the general 

 term, "plant-metabolism," his views may be said to be 



of Sachs. Among the latter are many who express the hope 

 of bring aide to trace the course of the changes connected with 

 these processes in such a manner as to prove by actual weight 



There are no text-b 

 a few elementary 



one" 



>n plant phy 



in which th 



through some mode of re 



asoning eithe 



or show how it ma 



y possibly be pro^ 



process of CO., assimilatio 



11 as it is cal 



tion is formed whi 



ch m 



ay, or may i 



undergone in this 





e process. 1 



arbitrary, no proof 



whate 



ver can be gi 



that it expresses hoi 



vtlie: 



relations in igl 



more difficult mal 



cter is 



i undertaken 



explain the process 



occur 



ring in the ch 



tion. All the Ger. 



man i 



text books, £ 



Reinke, Detmer an. 



1 otic 



T8, all have ti 



thesis which may e 



xplaii 



i the exact m 



which the rhythm ■ 



>Uh->\ 



;raetive and i 



is kept up in the li\ 



ing p 



.. 



^t^an^mtatu^ 



'l-Hh 



able to carry 



