WHY WAS THIS THEORY NOT STATED BEFORE 251 



Besides Loeb's work and the work of others on 

 artificial parthenogenesis, much other work also has 

 been done which indicates that morphology is of only 

 secondary importance. Thus, for example, as Wolf- 

 gang Pauli insists, the concept of a boundary phase 

 has to do service in the absence of histologic evidence 

 of a membrane between different tissue constituents. 

 Then there are the experiments on the growth and 

 form modifying tropisms of plants (J. Sachs), and 

 of organs of certain animals (Loeb^). One also may 

 recall Brown-Sequard's classic experiments and 

 theories on sex-gland transplantation (1888), and 

 the earlier (1849) experiments of Berthold, who 

 found that a hen into which the testicles of a young 

 cock had been transplanted, developed secondary 

 sex characteristics — masculine voice, love of combat, 

 etc. 



But the trend away from morphology in biology, 

 and the substitution of the methods of physical 

 chemistry for those of morphology, is not the end. 

 Life, the organism, cannot be interpreted adequately 

 in terms of physical chemistry any more than in 

 terms of morphology. This does not mean that, 

 depending on the method of approach, the organism 

 may not be described as a series of chemical reactions, 

 the rate of progression of which, in some organisms 



' Forced Movements, Tropisms, and Animal Conduct. 



