ON THE RELATIONS OF MAN WITH THE LOWER ANIMALS 491 
compared only with the brain of a white who is idiotic from an arrest 
of cerebral development.”—p. 66. 
Finally, with respect to the fourth difference, Tiedemann observes 
(p. 515) of the negro’s brain :— 
“The anterior part of the hemispheres is something narrower than 
is usually the case in Europeans. This is particularly remarkable in 
the brain of the Bosjes woman.” 
Thus, the cerebral hemispheres of the Bosjesman (and to a certain 
extent of the negro), so far as the evidence before us goes, are differ- 
ent from those of the white man; and the circumstances in which they 
differ—viz., the more pointed shape of the cerebral hemispheres, the 
greater symmetry of their convolutions, and the different development 
of certain of these convolutions,—are all of the same nature as most of 
those which distinguish the ape’s brain from that of man. In other words, 
if we place A, the European brain, B, the Bosjesman brain, and C, the 
orang brain, in a series, the differences between A and B, so far as they 
have been ascertained, are of the same nature as the chief of those 
between B and C. 
The brains of the lowest races of mankind have been hardly at all 
examined ; and it would be a matter of great interest to ascertain 
whether, in these races, there is any trace of the external perpen- 
dicular fissure, any diminution of the lobule of the marginal convolu- 
tion, and any increase of the proportional size of the nerves to the 
cerebral mass. Medical men living at the Cape of Good Hope, in 
Australia, and within reach of the Hill-men of India, will, it is to be 
hoped, some day solve these problems for the zoologist. 
Let it be admitted, however, that the brain of man is absolutely 
distinguished from that of the highest known apes— 
Ist. By its large size, as compared with the cerebral nerves ; 
2nd. By the existence of the lobule of the marginal convolution ; + 
3rd. By the absence of the externa! perpendicular fissure— 
And then let us turn to the other side of the argument, and weigh 
these differences against those which separate the brains of Pzthecus or 
Troglodytes from those of the lowest Quadrumana. 
The brain of Lemur mongos is well figured, and constantly referred 
to by Tiedemann in the “ Icones” so often referred to. The few gyri ; 
the shortness of the cerebral hemispheres, in the region of the third 
lobe, which leave fully half the cerebellum uncovered ; the large size 
of the vermis superior; the prominence of its flocculus; the great size 
of the olfactory nerves, which rather deserve the name of olfactory 
1 The second and third differences are mentioned by Gratiolet, to whose Memoir I must 
refer for a statement of their nature. 
