342 



THE AMERICAN NATURALIST 



[Vol. LIU 



A line of argument which has points of similarity to 

 the foregoing has been independently developed by 

 Holmes.^ ^ He believes: 



The hannoiiioiis fiiiiclioniiig of an organism is mainly secured by a 



in manner more or less remotely analogous to the governor of a steam- 

 engme or the forces which regulate the motions of the planets. ... In 



by the reactions thus brought about by other, and especially the con- 

 tiguous structures. If we suppose that the various cells constituting 

 the body have each a different kind of metabolism, and that the products 

 of each cell are in some way utilized by the neighboring cells, so that 

 each derives an advantage from the particular association in which it 

 occurs, we may understand, in a measure, how this checking may be 

 brought about. 



And here an analogy is pointed out with the relations 

 which obtain in ' ' symbiotic ' ' communities, such as those 

 composed of animal cells and certain unicellular algae. 



The conception here developed is in some respects an 

 extension of Roux's intra-selection hypothesis, though 

 Holmes rejects the notion of a ''struggle of the parts." 

 This conception, which derives strong support from re- 

 cent discoveries respecting ''hormones," gives a certain 

 measure of concreteness to that rather vague expression, 

 "the organism as a whole." For, despite the many 

 known instances of local autonomy, we can not doubt 

 that the organism does in a high degree act as a whole. 

 But this "wholeness" may not be an irresolvable fact, as 

 has sometimes been assumed. It may be possible to con- 

 ceive it in terms of chemical and structural integration."" 



This hypothesis, as applied to form regulation, would 



^^ Archiv f ur Entuyicklungsmechanil; 1904. 



17a To me, such a viewpoint seems quite reconcilable with the "organis- 

 mal" conception of Eitter, though Professor Eitter himself (The Unity of the 

 Organism, Vol. I, p. 183) has gone to considerable pains to show the fallacy 



