391 



maun,* and of the extended series of inquiries of Sir W. Hamil- 

 tonf of Edinburgh, Mr. Sims, J 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 

 encrusting 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, whicla 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 hu^nan 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, 



• Phil. Trails. 1836. f Munroe's Anat. of Brain, 1831, p. 4. 



t Med. Chir. Trans, vol. .\i.x, p. 359. 



§ Lond. and Edinb Monthly Journal of Med. Sci., April, 1843. 



