48 W. BLAXLAND BENHAM. 



After the brain had been described it was purchased by 

 Professor Lankester for the Oxford University Museum ; and 

 my attention was particularly directed to it when comparing 

 the convolutions of the anthropoid apes with those of man, for 

 the purpose of exhibiting in the museum a series of anatomical 

 preparations illustrating the relations of man to the apes. 



One of the most striking features about '' Sally's " brain is 

 the absence of a well-defined " occipital operculum," the 

 presence of which was supposed by Gratiolet to mark off the 

 chimpanzee brain very strongly from that of the orang, in 

 which it is generally absent. With this disappearance of the 

 operculum is connected certain other modifications in this 

 region of the brain, the most evident of which is the diminu- 

 tion in the extent of the so-called " Affenspalte " or Simian 

 fissure, and the consequent resemblance of this region of the 

 brain to that of the orang and of man. Gratiolet placed the 

 chimpanzee further from man than the orang, but " Sally^s " 

 brain is considerably more human than that of any orang 

 hitherto figured, and it becomes a matter of great interest to 

 compare the gyri and sulci in the brain of this specimen with 

 those of the more ordinary chimpanzee on the one hand and 

 with those of man on the other. In making these comparisons 

 I have the advantage over Beddard in that I am able to make 

 use of the valuable and extensive researches of Dr. D. J. 

 Cunningham, published in 1892, just after Beddard's com- 

 munication to the Zoological Society ] and in the present paper 

 I shall adopt Dr. Cunningham's nomenclature, which is in 

 agreement generally with that employed on the Continent. 



My great indebtedness to Dr. Cunningham's work is 

 sufficiently evidenced by my constant reference to it. 



I. Historical. 

 Descriptions, more or less detailed, of the brain of the 

 chimpanzee are fairly numerous. I append a bibliography of 

 the more important papers ; but amongst those described I 

 have only been able to light upon two brains bearing any close 

 resemblance to that of " Sally.'' One of these is described and 



