450 PHYSIOLOGICAL SERIES. 



expanding arcus occipitalis, which is still partially sub- 

 merged. 



In this brain there seems to be a definite inferior 

 occipital sulcus which is joined to the parallel sulcus. 



There is no ventricle of Verga in this specimen. 



Beddard, Proc. Zool. Soc. 1899, p. 71, fig. 5. 



D. 660. The brain of a Gorilla, cut in mesial sagittal section. 



The condition of the insular region in this is essentially 

 the same as in the preceding specimen. But more of the 

 insula and much more of the superior limiting sulcus are 

 exposed. Nor does the mesial extremity of the fronto- 

 orbital (anterior limiting) sulcus become hidden by the 

 temporal pole, so that the insula can be seen passing into 

 continuity with the locus perforatus. The superior limiting 

 sulcus gives off a deep, short branch cutting into the 

 insula on each hemisphere. 



The two great T-shaped complexes of inferior precentral 

 and inferior frontal sulci and superior precentral and 

 superior frontal sulci respectively are disposed with dia- 

 grammatic simplicity, especially on the right hemisphere. 



The other sulci of this brain agree in arrangement with 

 those of the last specimen. The intraparietal sulcus, how- 

 ever, is joined to its ramus postcentralis superior on both 

 sides ; and a series of compensatory intraparietal sulci are 

 found which are not exactly comparable to those of the 

 other brains. 



Beddard, op. cit. p. 73, fig. 7. 



D. 661. The brain of a Gorilla (Anthropopithecus gorilla). 



The insular region resembles that of specimen D. 659. 



The inferior precentral and inferior frontal sulci ;m> 

 fused. The superior frontal sulcus is subdivided into two 

 parts of which the posterior is joined to the superior pre- 

 central and also (on the right side) to the inferior frontal. 



The intraparietal sulcus resembles that of the last 

 specimen. 



In the foregoing accounts it was suggested that there 

 was some reason to regard the lateral sulcus of Carnivores 

 as the intraparietal, the ansate as its ramus postcentralis 



