544 
PROFESSOR MABSHALL ON THE BRAIN OF A BUSHWOMAN; AND 
the corpora striata have been more especially involved. Fourthly. The original vice of 
formation, in all probability, affected these two pairs of ganglia primarily; and this 
entailed, as a necessary consequence, an interrupted, irregular, defective, and perhaps 
retarded evolution of the convolutions of the hemispheres themselves. Fifthly. The 
primitive starting-point of the future idiotic condition dates from a period far earlier than 
that at which all further evolution ceases ; and in fact, as regards the optic thalami and, 
especially, the corpora striata, probably from a very early period of development indeed. 
This conclusion is obviously more acceptable to the physiologist (because more consistent 
with the radical deficiency in cerebral power manifested by idiots) than the supposition 
that the idiotic state should be due to a sudden arrest of a previously normal develop- 
ment at some later period of foetal life. Sixthly. The anatomical connexion which, by 
the comparison of these idiots’ brains with healthy foetal brains, has been shown to exist 
(in human brains, at least) between the development of the corpora striata and the frontal 
lobes, and the optic thalami and the temporal and parietal lobes, has a considerable 
general interest, and probably has a physiological significance which may hereafter 
throw light on the functions of the convolutions of those several parts. Lastly. The 
deficiency in the corpora striata and the associated frontal lobes becomes particularly 
interesting when we reflect on the special connexion of those ganglia with the anterior 
or motor columns of the cord, and on their probable intimate concern in the execution of 
voluntary movements, i. e. in the mechanical expression by the body of those numerous 
acts which are the outward exponents of that important psychical faculty commonly 
designated “ the will.” Now, it is the inadequate performance or entire abrogation of 
those acts, whether locomotive, manipulative, or articulate, which constitutes one of the 
most striking characteristics of the idiotic state. 
7. It is impossible, in the present state of our knowledge, to determine the interesting 
question whether some parts of the idiots’ cerebra had undergone, after the general 
arrest of ordinary morphological changes, further local development, as the result of 
use or ordinary training. 
8. There are, however, certain evident grounds for inferring that, after the cessation 
in these cerebra of all further evolutional changes, they experienced an increase of size, 
or a mere growth of their several parts. Thus the idiots’ cerebra are considerably larger 
than foetal cerebra in which the convolutional development is at a similar stage ; whilst 
the individual convolutions themselves, the same in number, are necessarily broader and 
deeper. Again, from Dr. Boyd’s observations, it appears that in a certain number of 
foetuses prematurely born, with an average height of 14 inches for males and 13 ‘5 for 
females, whose brains would about correspond with the idiots’ degree of convolutional 
development, the average weight of the cerebrum in the former was 5*33 oz., and in the 
latter 4*42 oz. ; whereas, as we have seen, the idiot boy’s cerebrum weighed 5-85 oz., 
and the idiot woman’s 7*63 oz. The greatest difference is in the case of the woman, who 
lived to the adult age ; whilst the boy, it must be remembered, died at the age of 12. 
9. It has been shown that the temporal region preponderates in the idiot woman, 
