No. 514] 



NOTES AND LITE B . 1 Ti l; E 



623 



present a more thoroughly incorrect account of another's work, 

 both as to material facts and as to general views and principles, 

 than Bohn has given of my own. A citation of some typical 

 examples will enable the reader to form an idea of the authors 

 practise and ideals of accuracy. 



Any one acquainted with my work on the reactions of lower 

 organisms will recall that I found and set forth, with what 

 seemed to many wearisome repetition, that the cause of reaction 

 is in a large proportion of cases a change in external conditions, 

 variation in concentration of chemicals, in degree of tempera- 

 ture, intensity of illumination, etc. Now, Bohn has likewise 

 observed this (as had many previous workers), and he makes 

 large use of it in explaining behavior; under the name of 

 "sensibility differentielle'' it forms one of his three main factors 

 in behavior. He is even inclined to lay claim to a certain 

 originality in this. 9 



Amid the ruins [of other men's ideas] the reader, I hope, 

 will see already some new constructions arising. Certain chap- 

 ters, those consecrated to vital rhythms and to sensibility to 

 differences figure for the first time in a book on comparative 

 psychology (p. 3). 



For this purpose it is convenient that he feels prepared to 

 assert that I had never recognized this as a cause of reaction! 



The idea of sensibility to differences has escaped Jennings. 10 In gen- 

 eral, Jennings has not carried far enough the analysis of the move- 

 ments of the lower organisms ; as he has not taken account of th<^ phe- 



and error." 11 



Such statements appear again and again throughout the book, 

 and form the basis for repeated condemnations of my work. It 

 would be difficult to make statements more completely contrary 

 to the facts. As this is the source of most of Bohn's mistakes 

 in regard to my work, it is well to consider the matter in some 

 detail. 



No doubt is left as to what is meant by "sei 



entielle" ; it is discussed in full with numerous ex 

 9 Though he recognizes that Loeb had made use of tl 

 10 " La notion de sensibilite differentielle a echappe a 

 11 " D'une facon generate, Jennings n'a pas pousse i 



; the 



