316 RESEARCHES ON CORTICAL LOCALISATION AND 



neopallial representation is thus, as regards structure, a repetition 

 of the hippocampal type granular and infra-granular cortex. By 

 the accrescence of a supra-granular layer of varying degrees of depth 

 and complexity of its component nerve cells, different grades of repre- 

 sentation may be reached, and are reached to some extent in the 

 same animal, even if this occupies a lowly place in the mammalian 

 phylum, and to a greater extent the higher is the position in the scale 

 to which the animal belongs." 



To summarise and correlate the mass of histological data which 

 bears on mammalian cortical localisation from the aspect of 

 cerebral function would be beyond the scope of this article. Many 

 of the observations of the several authors differ greatly in detail, 

 as is naturally to be expected in the case of a subject still in its 

 infancy, and some are contradictory. Further, the greater part 

 of the published work deals with histological observations rather 

 than with physiological deductions. It is thus not yet possible to 

 properly correlate the results of the various investigations which 

 deal with animal behaviour under different conditions, and the 

 deductions which may be drawn from them with regard to the 

 psychic processes which take place in the different members of 

 the various natural orders, with the histological data which have 

 hitherto been obtained with regard to the cerebra of the mammalia. 



EVOLUTION OF CEREBRAL FUNCTION 



The following broad statements, with regard to the mode of 

 evolution of cerebral function, are, however, possible, if they be 

 regarded in the light of a partially proved provisional hypothesis. 



The term " neopallium " has been introduced by Elliott Smith 

 to designate the cortex cerebri which is peculiar to mammals, and 

 which consists of a variable area intercalated between the pyriform 

 lobe and the hippocampus. This term is employed in contra- 

 distinction to the " archipallium " of the lower vertebrates. The 

 neopallium increases in amount with the ascent of the mammalian 

 scale, and in man constitutes almost the whole of the cortex 

 cerebri. 



The functions of the neopallium are the reception of sensorial 

 stimuli, the conservation of associative memory, the performance 

 of the higher psychic processes, and the evolution of the com- 



