1899.] 



BRAIN OP THE GORILLA. 



09 



some importance. The Y-shaped fissure was visible on the mesial 

 surface, and between the forks of the Y extended dotvn for a short 

 distance from the upper surface of the brain a fissure. The 

 arrangement, in fact, is closely like that figured by Benham in 

 figs. 24 and 29 of his paper. I shall follow him in terming the 

 short middle fissure the lateral parieto-occipital and the Y-shaped 



Tis. 3. 



Brain of Gorilla belonging to the University of Oxford. Dorsal view. 

 Op. Operculum. Other letters as in fig. 1. 



fissure the mesial parieto-occipital. I have used the expression 

 "apparent difference" to distinguish this hemisphere from that 

 in which the sum total of the parieto-occipital fissures was 

 represented by one Y for a good reason. When the furrow of 

 that hemisphere is explored by pushing aside its margin a median 



