16 



INTRODUCTION. 



Seeing, then, that the size of the brain, in comparison with that of 

 the body, could not be taken as the test of intellectual endowments, 

 Soemmerring proposed, between Man and other animals, a criterion, 

 which he considered to be much less deceptive than a comparison of 

 the body with the brain ; namely, that of the brain with its own nerves.* 

 His theory is, that, as far as mere animal existence is concerned, a 

 small portion of the brain is sufficient to influence the nerves ; and that, 

 therefore, the surplus quantity beyond this small portion (a portion not 

 determined) will be available for the purposes of intellectual operations ; 

 so that where the greatest surplus exists, there the highest intellectual 

 capacity will be enjoyed. Man, for instance, whose bodily powers are 

 only moderate, has the largest brain in proportion to the nerves, and 

 to the demand made upon their agency, as regards mere animal life. 

 After Man come the Simiae. As a further illustration of his position, 

 to which he says he was conducted by a most careful and accurate 

 comparison of a great number of brains, he remarks, that the largest 

 Horse's brain in his possession weighed one pound seven ounces, 



Ouistiti, as 



Coita 



Macaque 



Magot 



Vari 



Bat 



Mole 



Bear 



Fox 



Ferret 



Beaver 



Hare 



Rat .'...'..".'.'.".'..."..".."..'...' 



Mouse 



Field Mouse 



Elephant 



Sheep from 1 to 192 to 



Ox from 1 ... 750 to 



Horse from 1 ... 400 to 



to 



25 to 1 



28 



... 41 



... 86 



... 105 



... 84 



... 96 



... 36 



... 265 



... 205 



... 138 



... 290 



... 228 



... 76 



... 43 



... 31 



... 500 



... 351 



... 860 



... 700 



... 254 



... 102 



Dolphin ............................................................ from 1 



Among birds, in the Eagle, the proportion is as 1 to 260 ; in the Falcon as 1 to 102 ; in the Goose as 1 to 

 360 ; in the Cock as 1 to 25 ; in the Red-breast as 1 to 32 ; in the Chaffinch as 1 to 27 ; in the Sparrow as 

 1 to 25 ; and in the Canary bird as 1 to 14 : among reptiles, in the Frog as 1 to 172 ; in the Tortoise as 1 

 to 2240 ; in the Turtle as 1 to 5688 ; and among fishes, in the Carp, as 1 to 560 ; in the Pike as 1 

 to 1305 ; in the Shark as 1 to 2496. HALLER, El. Phys., 1. x. s. 1. EBEL, Obs. Neu., in LUDWIG'S 

 Script. Neu., vol. iii. p. 150. SOEMMERRING, Korp. ver. Neg. v. Eur. p. 61. CUVIER, Anat. Comp. 

 Led. ix. art. 5. LAWRENCE, Lect. p. 123, note. 



* " Desmoulins is of opinion, that the brain decreases in size in old people. From this circum- 

 stance he explains the diminution of the functions of the nervous system and intellectual powers. 

 The truth of this assertion has not, as yet, been determined. The brothers Wenzel and Hamilton 

 deny it. It is remarkable, that the brain of a Man, eighty-two years old, was very small, and weighed but 

 three pounds two ounces two drachms ; and the brain of a Woman, about eighty years old, weighed 

 but two pounds nine ounces one drachm. I have generally found the cavity of the skull smaller in 

 old Men than in middle-aged persons. It appears to me, therefore, probable, that the brain really de- 

 creases in old age, only more remarkably in some persons than in others." Professor Tiedemann, on 

 the Brain of the Negro; Phil. Trans. Royal Soc. Part n. 1836. 



