CHILD'S " SENESCENCE AND REJUVENESCENCE " 

 AND "INDIVIDUALITY IN ORGANISMS"* 



C. JUDSON HERRICK 



Students of behavior are perforce interested in the question 

 of the underlying causes of behavior. Here, as in other fields 

 of biology, there are doubtless many who would prefer to turn 

 such problems over to the philosophers, whose special province 

 it is to deal with questions of teleology and other basal postu- 

 lates. But even philosophers need facts upon which to base 

 their general reasoning. And the insistent intrusion into be- 

 havioristic literature of works on objective psychology and 

 mechanistic conceptions of life, on the one hand, and of doctrines 

 of orthogenesis and vitalism with their entelechies and other 

 metaphysical daemons, on the other hand, shows that these 

 theoretical questions not only lie in the background but often 

 also in the foreground of research in behavior, sometimes playing 

 a decisive part in the shaping of a research program. 



Few investigations of recent times have yielded more positive 

 factual contributions to the problems of the organization and 

 fundamental behavior of living things than have those of Child 

 as reported in the two volumes recently published by the Uni- 

 versity of Chicago Press and the extensive series of special papers 

 upon which these volumes are largely based. Many phenomena 

 which in the past have been confidently cited by the vitalists 

 as demonstrative proofs of the impossibility of mechanistic 

 explanations are in these works shown to be the natural ex- 

 pressions of a mechanism of extreme simplicity whose operations 

 yield to experimental control and explanation with all desirable 

 objectivity. 



Some years ago Jennings summed up his very illuminating dis- 

 cussion of the regulatory processes in organisms in the aphor- 



* Child, Charles Manning. Senescence and Rejuvenescence. The University 

 of Chicago Press, 1915, 481 pages, price $4. 



Child, Charles Manning. Individuality in Organisms. The University of Chi- 

 cago Press, 1915, 213 pages, price $1.25. 



