AND AFFINITIES OF THE GORILLA. 269 



Gorilla. Negro. 



in. lines. in. lines. 



Length of cerebrum 4 10 6 3 



Breadth of cerebrum 3 9 4 10 



Depth (greatest vertical diameter) .... 2 6^ 46 



Breadth of cerebellum 3 4 3 7 



Length of cerebellum 110 2 3 



Depth of cerebellum 1 4 1 8 



In these admeasurements some deduction from the Gorilla's brain must be made for 

 the thickness of the dura mater and other membranes included in the cast : that of the 

 Negro's brain showed it stripped of its membranes ; and the admeasurements are from a 

 subject corresponding with the smallest of those figured by Tiedemann in the ' Philo- 

 sophical Transactions ' for 1836, pi. 31, in which the posterior cerebral lobes extend 

 half an inch beyond the cerebellum. 



Although in most cases the Negro's brain is less than that of the European, I have 

 observed individuals of the Negro race in whom the brain was as large as the average 

 one of the Caucasian ; and I concur with the great physiologist of Heidelberg, who has 

 recorded similar observations, in connecting with such cerebral development the fact 

 that there has been no province of intellectual activity in which individuals of the pure 

 Negro race have not distinguished themselves. The contrast between the brains of the 

 Negro and Gorilla, in regard to size, is still greater in respect of the proportional size of 

 the brain to the body — the weight of a full-grown male Gorilla being one-third more 

 than that of an average-sized Negro. 



Passing from this contrast to a comparison of the Gorilla's brain with that of other 

 Quadrumana, we discern the importance and significance of the much greater difference 

 between the highest Ape and lowest Man, than exists between any two genera of Qua- 

 drumana in this respect: the brain of the Gorilla, in the contraction of the anterior lobes, 

 in the non-development of posterior lobes extending beyond the cerebellum, and in the 

 paucity, symmetry, and relative size of the cerebral convolutions, closely accords with 

 the brain of the Chimpanzee. From these to the Lemurs the difference of cerebral 

 development shown in any step of the descensive series is insignificant compared with 

 the great and abrupt rise in cerebral development met with in comparing the brain of 

 the Gorilla with that of the lowest of the Human races. This difference parallels that 

 in the structure of the lower limbs, especially the foot, in the Gorilla and Man ; on 

 which difference, as exemplified in the Chimpanzee and lower Apes and Monkeys, 

 Cuvier founded the ordinal grade to which he assigned the genus Homo, under the term 

 Bimana. The disposition of the hallux as a hinder thumb, with the concomitant modi- 

 fications of the tarsal bones, are as strongly marked in the Gorilla as in any lower Qua- 

 drumane, and the contrast between the foot-structures of the Gorilla and Negro is as 

 great. 



2 N 2 



