456 'Journal of Comparative Neurology and Psychology. 



study of the whale brain in its psychological relations informs 

 me that these animals, which in life are entirely beyond the 

 reach of investigation, do not possess the olfactory sense, but 

 that they are able to behave associatively and intelligently by 

 means of impressions received through the trigeminal nerve. 



Now it would be of the greatest importance if we also knew well 

 the anatomy and functions of the parts of the neopallium, because 

 the differences between the human brain and the brain of other 

 mammals depend essentially upon the degree of its development. 

 In spite of the general impression that the mammalian cortex is 

 well understood, not only anatomically, but, through numerous 

 and celebrated experiments, also physiologically and clinically, I 

 must here assert that we know surprisingly little as soon as one 

 inquires how much our knowledge tells us about its functions. 

 It is only in recent years that the researches of FLECHSichave 

 shown us how extensive is the region of the cortex which we must 

 regard as essentially the association field. Purther, the works of 

 S. Ramon y Cajal, Brodmann, Mott, Campbell, and others, 

 have contributed much new information regarding the cortex of 

 the most different mammals. Only recently has it been success- 

 fully demonstrated that definite parts of the cortex exhibit definite 

 characteristic structures. We do not yet know the function of 

 the majority of the cortex fields which are today distinguished, 

 which looks rather badly for our knowledge of the functions of 

 the cortex. But there are two definite structures whose roles are 

 so wellunderstood that wherever these structures are encountered 

 one may expect the same functions. These are the so-called motor 

 cortex and that type of cortex which encloses the visual areas. 



Here we stand at the very beginning of important and necessary 

 researches and one can only point out where they may possibly 

 lead. It is, however, absolutely necessary that we undertake 

 them, for only such investigations, carried on at the same time 

 both anatomically and psychologically, can help us where observa- 

 tions of the living animal are impossible. I here call attention to 

 the huge brain of Tursiopsis tursio, a dolphin, of which we know 

 little more than that it swims about ships. Its much folded sur- 

 face is doubtless much greater than that of the human brain. But 

 of its operations we know absolutely nothing. It is entirely con- 

 ceivable, however, that further adequate study of the cortex may 

 show us what its possibihties are. The same thing holds true for 



