520 PROFESSOR MARSHALL ON THE BRAIN OF A BUSHWOMAN; AND 
in convolutional development, between the Bushwoman’s brain and the European brain, 
than between the lowest and highest quadrumanous brains. If, indeed, we disregard 
the general differences of size and complexity, and look only to those which have been 
considered as special peculiarities, such as the existence of the supramarginal lobule, 
and the joint relative development of the two upper connecting convolutions, there is 
less difference between the Bushwoman and the European than between the Chimpanzee 
and the Orang. But perhaps it is premature yet to decide this latter point. It is cer- 
tain, however, that there is less difference in convolutional development between the 
Bushwoman and the highest Ape, than between the latter and the lowest quadrumanous 
animal. 
7. Finally, the establishment of the conformable development of the brains of the 
Bushwoman and Hottentot Yenus (herself believed by G. Cuvier to have been a Bush- 
woman of small stature) is a step gained in cerebral anatomy; and their common infe- 
riority to the European brain may justify the expectation that future inquiries will 
show characteristic peculiarities in degree of convolutional development in the different 
leading races of mankind. 
e. Internal Structure of the Cerebrum and Cerebellum. The Commissures , Cavities , 
Ganglionic masses, and Laminae , studied on the Preserved Brain. 
The cerebrum. — The general depth of the sulci in the Bushwoman’s brain is rather 
more than half an inch ; they are deepest on the parietal region, shallower in the frontal, 
and, with the exception of the posterior part of the fissure of the hippocampi, are shal- 
lowest on the occipital lobe. They are deeper on the outer than on the inner surface 
of the cerebrum ; they are very shallow on the under surface near the tip of the tem- 
poral lobe, and also on the orbital surface of the frontal lobe. In these respects the 
Bushwoman’s brain conforms to the usual conditions. 
The average thickness of the grey matter is nearly -g^-ths of an inch, the extremes 
being -^ths and .nearly - 3 %ths of an inch. The thickest grey matter is in the frontal and 
parietal regions, the thinnest at the tip of the occipital lobe, as usually found in both 
human and quadrumanous brains. The proportion of white matter in the centre of the 
hemisphere (see Plate XIX. fig. 6), which forms, on a horizontal section, the centrum 
ovale, appears smaller than in the European — a condition which coincides with the 
comparative narrowness of the brain. Both the grey and the white substance are 
darker than in the European, having a peculiar yellow tint. There was much pigment 
here and there in the membranes. 
The corpus callosum (Plate XVIII. fig. 4, c) is long, but is wanting in general depth 
and in thickness at each end. As measured in the hardened brain, in thirtieths of an 
inch, its length, its greatest thickness, its least thickness, and its average thickness are 
represented by the numbers 78, 13, 5, and 6 ; whilst in the European the corresponding 
dimensions are 93, 16, 6, and 13; in the Chimpanzee I found them to be 51, 6, 2, and 
4*5. The sectional area of the longitudinally divided corpus callosum is therefore in the 
