Chapter XXIII 



A Still Closer Look at the Organismal Nature of Tropisms 



HAVING selected tropisms as a strategic point in our 

 program of search for the vital connection, if such 

 exists, between the physical and the psychical, we must turn 

 again to this subject. Our previous treatment of the tro- 

 pism theory brought out the essential organismal character 

 of the type of activity to which the term tropism has. been 

 applied. The result of tha"t treatment might be epitomized 

 by saying that in so far as the theory rests on accurate 

 and adequate description, it is genuinely organismal and 

 genuinely sound, but in so far as it rests on causal ex- 

 planation that is elementalistic in spirit and expression it is 

 genuinely unsound. Our present aim will be furthered by 

 illustrating this epitomized stricture on the theory in a little 

 different way from which we objectified our criticism in the 

 earlier treatment. 



Every one familiar with current explanatory discussion 

 of tropisms must have noticed the large and free manner in 

 which the word substances is made use of in the explanations. 

 Thus, to illustrate: The larvae of certain butterflies emerge 

 from their winter nests under the influence of the warm 

 spring sunshine, crawl to the tips of the branches of some 

 shrub or tree, eat the buds and tender leaves there; then, 

 after feeding to satiety "turn tail" and crawl down the 



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