32 ON THE AFFINITIES AND DIFFERENCES BETWEEN THE 



broad ; the simious is taper because it is narrow; the human outline 

 is, viewed from above, irregular, but its irregularity is due to 

 elongation, and is not merely a sign but a source of power ; the 

 ape's conforms more closely to the egg-type, but conformity to 

 type is here in actuality, as in ontology, but a limitation of 

 capability. 



A profile view of the two brains, such as you may take from 

 the diagrams, disregarding the letters and numbers, may have 

 many of its results expressed in much the same terms. The 

 human brain presents along its upper surface a long gradually- 

 sloping table-land, which reaches its highest point a considerable 

 way behind the middle point of the long axis of the organ. The 

 line limiting the superior edge of the simious brain is all but a 

 semicircle. Looking now at the inferior boundary line of the two 

 hemispheres, we see that regularity and evenness have removed from 

 the lower and become the characteristics of the higher brain. The 

 unevenly projecting prominence numbered 7 and 8 is much larger 

 relatively to the part of the brain which lies above it and 

 before it in the ape than in man. This irregularity is due partly 

 to excess, the anterior and posterior excavations in the ape's lower 

 boundary line are due to defect of development rather than to the 

 reverse. These points of difference are quantitative, they are con- 

 siderations of more or less ; and it is only fair to observe that the 

 lower of the two human brains differs as to these very points to 

 some extent, though not by any means to the same extent from the 

 higher as the simious brains do from it. The often-mooted point 

 of the overlapping or non-overlapping of the lower or after brain, 

 the cerebellum by the cerebral hemispheres, may be set at rest by a 

 reference to these diagrams. The cerebral hemispheres of the 

 Hottentot's brain are seen to project further beyond the cerebellum 

 than do the cerebral hemispheres of the white man's brain. The 

 marmoset brain, albeit its owner was but squirrel-like in intelli- 

 gence, as in outer form, has a largely overlapped cerebellum ; the 

 length of its hemispheres being 2 T V'j the extent to which they pro- 

 jected beyond the cerebellum was J". The squirrel monkey, properly 

 so called (Callithrix sciureus), indeed outdoes the marmoset, its cere- 

 bral hemispheres overlapping the cerebellum by as much as one-fifth 

 of their length l ; and its superiority of intelligence we might be 



1 St. Hilaire, ' Hist. Nat.' ii. i. 249. 



