164 ARBOREAL MAN 



Kappers demonstrated its reality, to the pallial areas in 

 the cerebral cortex, where these ganglionic masses gain 

 re-representation. 



There is an order in cortical representation of functions 

 which is probably brought about by the same agency as 

 that which determines the order of the basal ganglionic 

 masses. We have seen that the first function to gain a 

 representation in the cortical pallium is the sense of 

 smell, and we have pictured snout- tactile impressions as 

 following in its train. It is therefore likely that tie 

 site of representation of these snout tactile impressions will 

 be in that part of the pallium which is in the immediate 

 proximity of the olfactory area. Likely, too, that the 

 associated mouth sense of taste will be in its near neigh- 

 bourhood. Further, since in the brain stem the motor 

 centres are attracted to sensory ones, it is likely that a 

 pallial area associated with snout movements will also 

 be developed in the neighbourhood of these sensory 

 nreas. We should now have a brain the cortex of which 

 consisted of an archepallial olfactory area, and grouped 

 in its immediate neighbourhood in the developing neo- 

 pallium areas devoted to the storing, sorting, and associa- 

 tion of impressions of taste, snout sensations, and snout 

 movements. So far, our outline of brain building has 

 been upon purely hypothetical grounds, but we can pass 

 from this stage to reality at any moment by examining 

 such functional charts as have been made of simple mam- 

 malian brains (see Figs. 64, 65, 66, 67 and 68). In the chart 

 of such an animal the rather large olfactory area, or arche- 

 pallium, has as its immediate neighbours in the neo- 

 pallium a taste area, and an associated area related to 

 tongue movements ; and a tactile area in which sensations 

 from the snout are stored, with, as a forward extension 

 of this, an area which, when stimulated, evokes snout 

 movements. We have now imagined a further develop- 

 ment in which the hand is added to the snout as a tactile 

 sensory organ, and in which the co-ordinated fine move- 



