TRANSACTIONS OF THE SECTIONS. 117 
the brain of a male European and Negro, and a cast of the interior of the cranial 
cavity of a full-grown male Gorilla; also figures of the bones of the feet of the 
Man and male Gorilla, in plates from his “ Memoir on the Osteology of the Gorilla” 
(Trans. Zool. Soc. vol. vy. pl. 11). 
The brain of the Gorilla, as exemplified by such cast, is of a narrow-ovate form, 
with the small end forward; the cerebrum does not extend beyond the cerebellum ; 
viewed with the lower surface of the medulla oblongata horizontal, it does not 
extend so far back as the cerebellum does. The difference of size between it and a 
small-sized Negro’s brain was exemplified in the subjoined admeasurements :— 
Gorilla. Negro. 
in, lines. in. lines, 
Length of cerebrum ........... “Songrich 4 10 6 3 
Breadth-of cerebrum’. ,%t.). 4. aca saat 3.9 4 10 
Depth (greatest vertical diameter) ...... 2 62 4 6 
Breadth of cerebellum ..... oth wotel s Merete 3.4 3.7 
Length of cerebellum ..........0.0005 1 10 2 5 
Depth of cerebellum <0... 0. ea onnwees 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 stript of its membranes; and the admeasure- 
ments are from a subject corresponding with the smallest of those figured by Tiede- 
mann in the ‘ Philosophical Transactions’ for 1836, pl. 32, 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, 
Tiedemann and the author of the present paper had observed individuals of the 
Negro race in whom the brain was as large as the average one of the Caucasian ; 
and the author concurred with the great physiologist of Heidelberg in connecting 
with such cerebral development the fact that there had been no province of intel- 
lectual activity in which individuals of the pure Negro race had not distinguished 
themselves. The contrast between the brains of the Negro and Gorilla, in regard 
to size, was 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, the author insisted upon the importance and significance of the 
much greater difference between the highest ape and lowest man, than existed 
between any two genera of Quadrumana 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, so far as they were indicated in the cast, closely 
accorded with the brain of the Chimpanzee. From these to the Lemurs the dif- 
ference of cerebral development shown in any step of the descensive series was in- 
significant 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 paralleled the difference 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 had founded the ordinal 
grade to which he had assigned the genus Homo, under the term Bimana. The 
disposition of the hallux as a hinder thumb, with the concomitant modifications 
of the tarsal bones, was as strongly marked in the Gorilla as in any lower Quadru- 
mane, and the contrast between the foot-structures of the Gorilla and Negro was as 
eat. 
The homologies of the parts in the structure of both brain and foot of the Human 
and Simial Mammalia being demonstrated, as by Tiedemann* and Cuviert, no 
; re aie parvus loco cornu posterioris.” (Icones Cerebri Simiarum, fol. p. 14, 
g. lil. 2. 
+ “Pouce libre et opposable au lieu du grand orteil.”  L’homme est le seul animal 
vraiment bimane et bipéede.’ (Régne Animal, i. p. 70.) ‘‘ Pedes hippocampi minores 
vel ungues, vel calcaria avis, que a posteriore corporis callosi tanquam processus duo 
