452 PHYSIOLOGICAL SERIES. 



of the latter may resemble that of Man quite as closely 

 as any Gorilla-brain. Those most competent to express an 

 opinion, regard the Chimpanzee as the nearest relative of 

 Man. Still the fact remains that the series of Gorilla- 

 brains in this Collection is certainly nearer the human type 

 than is the series of Chimpanzee-brains. 



I have so far referred only to the region of the "Affen- 

 spalte," because in all other parts there seems to be a close 

 agreement in the brains of the two species. 



The insular region is just as variable as it is in the other 

 Anthropoids. In the left hemisphere of this specimen, \\e 

 find the simple short exposed superior limiting sulcus, 

 approaching the fronto-orbital just as it does in the Gibbon. 

 On the left hemisphere, however, the exposed part of the 

 superior limiting sulcus is much longer (so that at a casual 

 glance it seems to join the fronto-orbital sulcus) and its 

 upper lip is markedly opercular. 



The right inferior precentral sulcus is very long and 

 approaches very close to the caudal end of the superior 

 frontal, and, to a great extent, usurps the place of the 

 superior precentral which is represented merely by the 

 short bifid caudal process of the superior frontal sulcus. 

 The long typical inferior frontal sulcus is joined to the 

 inferior precentral. 



On the left side, the inferior precentral is joined to the 

 ventral extremity of the central (Rolando's) sulcus. The 

 inferior frontal is not so long as on the right side, the 

 cephalic extremity being separated as a fronto-marginal 

 sulcus of Wernicke. Thus we have a curious reproduction 

 of what we may call the " Orang condition," such as we 

 have also seen in the left hemisphere of a Gorilla-brain 

 (D. 656). The middle frontal gyrus is broken up by 

 irregularly-placed sulci, but none of these can be strictly 

 called the middle frontal sulcus. 



Behind the sinuous central sulcus there is a typical 

 intraparietal complex, all the four constituent parts of 

 which are united. It passes posteriorly under cover of a 

 much more complete occipital operculum than any of the 

 eight Gorilla-hemispheres presents, and then joins the 



