391 
mann,* and of the extended series of inquiries of Sir W. Hamil- 
tont of Edinburgh, Mr. Sims,t and Dr. Reid.§ In considering 
the brain, however, in relation to the nervous function, many 
other circumstances are to be attended to beside the actual size 
or weight of the organ, namely, its weight compared with that 
of the body, the relative proportion of one part of the organ to 
another, as the cerebellum to the cerebrum, the relative size 
of the brain to that of the nerves connected to its base, and, 
above all, the structure of the organ, the size, number, and 
depth of the convolutions, and the extent and thickness of the 
enerusting lamina of the vascular, or grey vesicular neurine, 
which there are good reasons for believing to be the essential 
dynamic agent in the function of innervation. The weight 
of the human brain, compared to the weight of the whole 
body, is as one to forty-five or fifty, supposing the former to 
be about four pounds, and the latter to vary from 180 to 200 
pounds; whereas, the proportion in the elephant will be as one 
to 400 or 500, supposing the former to be twelve pounds, and 
the weight of the body to be only from two to three tons. 
The weight of the present specimen, which was by no means 
full grown, was about two tons. ‘Therefore, the human body 
is only forty-five to fifty times heavier than the brain, whereas 
the elephant’s body is four or five hundred times as heavy as 
its brain: then again the human cerebellum is much smaller 
than the cerebrum, being in the proportion of one to eight or 
nine, but in the elephant, the proportion is as one to two: 
therefore, the human cerebrum is eight or nine times larger 
than the cerebellum, whereas the cerebrum of the elephant is 
only twice as large as his cerebellum. These relative propor- 
tions are interesting and important, if, as we believe to be the 
case, the cerebellum be connected with the functions of the 
_ general muscular system, and the cerebrum with the manifes- 
tations of the mental principle. It must be admitted, however, 
— lie 
~ * Phil. Trans. 1836. + Munroe’s Anat. of Brain, 1831, p. 4. 
t Med. Chir. Trans. vol. xix. p. 359. 
§ Lond. and Edinb Monthly Journal of Med. Sci., April, 1843. 
