THE BRAIN. 167 



to require 600 nervous fibrils in one instance ; and in an- 

 other, half the size, 300 : further, that the animal with 600 

 fibrils possesses a brain of seven, and that with 300 a brain 

 of only five drams. To the latter we ought to ascribe 

 the larger brain, and a more ample capacity of registering 

 the impressions, made on the organ of vision. For allowing 

 one dram of encephalon to 100 fibrils, the brain, Vhlch is 

 absolutely the least, will have an overplus of two drams, 

 while the larger lias only one. That the eye, which is sup- 

 plied with a double quantity of fibrils, may be a more per- 

 fect organ of sense, will be readily admitted : but that point 

 is not connected with the present question^*.'* 



Independently of weight and size, Soemmerring ob- 

 served fifteen visible material anatomical differences be- 

 tween the brain of the common tail-less ape and that of 

 man f . 



It must be acknowledged, that the inquiries into the re- 

 lative weight of the brain and the body, and tiie comparison 

 between the former and the nerves connected with it, have 

 not yet afforded any precise and clear information respecting 

 the differences between man and animals, nor on the grounds 

 of the infinitely various faculties that distinguish different 

 animals. It can hardly be expected that these matters will 

 receive any clear elucidation, while we continue so ignorant 

 as at present of the functions executed by the different parts 

 of the encephalon. 



The basis of the position so much insisted on by Soem- 

 merring is an assumption that a certain bulk of nerve 

 requires always the same proportion of brain for the execu- 

 tion of its office — a datum by no means self-evident. The 

 comparison of the nerves to the brain in general is not satis- 

 factory : we should wish to know the relative proportions of 



• Ueher die Korperliche Verschiedcnhcit des Ncgers vom Europder ; p. 

 63—67. 



See also the dissertation of the same author, />e Basi Encephali; and 

 J. G. Ebel, Ohs. ISfcurol. ex Amt. Comparata, p. 17 ; Francof. ad Viadr. 

 1788; or in Ludwig Scriptorcs Ncurologid. 



f Utbcr die Korp. Vcrsch. p. 77, note. 



