GENETIC TYPE AND THE ENDOCRINES 569 



fications in performance are due to a change in the relation- 

 ship between the reflex systems as the behavior progresses. 

 The development of this relationship between the extraneous 

 forces and the reflex systems, and the change among the 

 systems in the course of the adjustment, is based on excitatory 

 and inhibitory processes. Each has a part in every modifica- 

 tion. The performance of the organismal systems was limited 

 to some extent by the experimental situation, but no attempt 

 was made to restrict the performance to one aspect of the 

 total behavioral pattern involved in this adjustment, or even 

 to keep any part of it, as the conditioned saliva, at a definite 

 magnitude. By following the same procedure with each ani- 

 mal, the differences in the course of the performance were 

 emphasized. The conditioned saliva is the only aspect quanti- 

 tatively observed, but this is not considered of any greater 

 importance than the muscular components of the behavior. 

 The significance of constitutional differences affecting be- 

 havior may be suggested by one part of the total behavior, 

 but by using more than one aspect, together with the course 

 of the adjustment, the interpretation is more evident. For 

 example, if an animal is of a highly excitable nature, this 

 is as evident in the performance of the muscular system 

 as in the salivary reaction. In the same way, if an animal is 

 of an inhibited type, this fact is evident in all factors of the 

 performance. The course of the behavior must be considered, 

 since a dog may have a relatively small conditioned salivary 

 reaction yet be an excitable animal. This was noted par- 

 ticularly in the case of dog 434 $ , a small animal. 



The results of the experiments divide the performances 

 of the animals into two outstanding types designated as 

 lethargic (group A) and active (group B), the two poles 

 of reaction. The performances of other dogs follow the same 

 general behavior characteristics of the polar groups, but to 

 a greater or lesser degree, and these dogs have been designated 

 lethargic type A-plus and active type B-minus. There seems 

 to be a continuous graded series in behavior from types 

 A to B. 



