314 BRAINS OF RATS AND MEN 



cesses are all confined to the cerebral cortex. In both 

 cases a large amount of reserve energy is expended. 



This is the physiological basis of so-called spon- 

 taneity and of impulse, the inner urge to action which 

 goes on with or without consciousness as a natural 

 expression of the structural organization 



The vital reserves of which we are here speaking 

 are by no means exclusively nervous functions. They 

 are common to all living organization. Each part of 

 the body has its own reserves which come to expres- 

 sion in local tone and spontaneity. And these local 

 expressions may in turn influence the general behavior 

 in very significant ways, as has been brought out in 

 numerous studies of the normal spontaneous activity 

 of the rat and the relations of the total amount of 

 spontaneous activity to physiological rhythms of the 

 gonads, hunger contractions of the stomach, etc. 

 (Slonaker, 191 2, 1924, 1925; Richter, 1922; Wang, 

 1923; Wang, Richter, and Guttmacher, 1925). Here, 

 also, should be mentioned the numerous studies of the 

 relation of behavior patterns to the maturation of the 

 related bodily organs, such as those of Stone (1922, 

 1924). 



Tracy (1926), in a careful study of the develop- 

 ment of the behavior patterns of the toadfish, has 

 observed the independent appearance of spontaneous 

 movements of a rather complex sort in different parts 

 of the body. It is at a distinctly later stage that these 

 local activities are knit together into a co-ordinated 



