198 ANTHROPOID APES. 



noted. In the lateral ventricles more of the charnc- 

 teristics described in the human brain are absent. 

 The four eminences resemble those of man ; nor does 

 the fourth cerebral ventricle present any remarkable 

 differences of form. Neither does the base or lower 

 surface of the brain display any important deviation 

 from the human type. The transverse section of 

 the nerves at their intersection appears to me, how- 

 ever, to be somewhat more oval than is the case in 

 man. 



There has recently been an attempt to recognize 

 a pithecoid character, or atavism, in microcephalic 

 men, the smallness of whose heads is allied with 

 a greater or less degree of idiocy. A pithecoid 

 structure of the brain has also been traced in several 

 individuals who are not microcephalous, but subject 

 to pathological affections. "We will first consider 

 those who belong to the latter category. Krause 

 examined the brain of an ape-like boy aged seven 

 years and a half, which, as the author remarks, 

 approximated in structure to the pithecoid type, 

 although without displaying microcephalic charac- 

 teristics. The two cerebral hemispheres were wanting 

 in symmetry ; they diverged from each other in the 

 region where the parieto-occipital fissure occurs on the 

 left cerebral hemisphere, and they formed an edge 

 which curved outward and backward so that the 

 cerebellum remained uncovered. On the lower 

 surface of the frontal lobes there was a strongly 

 marked ethmoidal prominence. Neither of the 

 fissures of Sylvius were closed, the left less so 

 than the right; the operculum was only slightly 



