AND AFFINITIES OF THE GORILLA. 269 
Gorilla. Negro. 
in. lines. in. lines. 
ikenethro cerebrumy. "ses eee ee e420 3 
Breadth of cerebrum . . Pe aS: 200 10 
Length of cerebellum 10 
n 
6 
woe 4 
Depth (greatest vertical diameter) 64 4 6 
3 
2 
Depth of cerebellum 4 1 
Ge CAE END 
Breadth of cerebellum . . . ..... 3 #4 
1 
1 
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, pl. 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. 
2n2 
