OF ANIMALS. 



ns 



Dr. Gall, whose physiological theory has excited so much attention of 

 kte years on the Continent, has endeavoured to account for all these 

 varieties of feehng, and, indeed, for all the animal senses of every kind, 

 both external and internal, by supposing some particular part of the brain 

 to be allotted to each, and that the general character and temperament of 

 the individual is the result of the different proportions which these different 

 parts or chambers of the brain bear to one another. He supposes, also, 

 that this orgaii is possessed of two distinct sets of nervous fibres— a secer- 

 nent and ail absorbent : both directly connected with what is called the 

 cineritious or asii-coloured part of the brain ; the former issuing from it 

 and secreting the fluid of the will, or ihat by wiiich the mmd operates on 

 the muscles ; and the latter terminating in it, and conveying to it the fluid 

 of the external senses, secreted by those senses themsel ves, and communi- 

 cating a knowledge of the presence and degree of power of external ob- 

 jects. This elaborate theory, and the facts to which it appeals, were very 

 minutely investigated a few years ago by a very excellent committee of 

 the physical class of the French National Institute, assisted by Mr. (now 

 Dr.) Spurzheim, the intimate friend and coadjutor of its inventor, and who 

 is well known to have contributed quite as much to the establishment gf 

 this speculation as himself This committee, after a very minute and 

 cautious research, gave it as a part of their report, that the doctrine of the 

 origin and action of the nerves is probably correct ; but that this doctrine 

 does not appear to have any immediate or necessary connexion with that 

 part of Dr. Gall's theory which relates to distinct functions possessed by 

 distinct parts of the brain.* The origin, and distribution, and action, how- 

 ever, of the nervous trunks have since been far more accurately traced out 

 by Mr. Charles Bell, M. Mageudie, and various other physiologists ; 

 while, in refutation of the doctrine that ascribes distinct functions to dis- 

 tinct parts of the brain, it may be sufficient to observe, for the present, 

 that many of the nerves productive of different functions originate in the 

 same part, while others, productive of the game function, originate in 

 different parts. 



There is no animal whose brain is a precise counterpart to that of man ; 

 and it has hence been conceived, that by attending to the distinctions be- 

 tween the human brain and that of other animals, we might be able to 

 account for tlieir different degrees of intelHgence. But the varieties are 

 so numerous, and the parts which are deficient in one aiiunal are found 

 connected with such new combii^atians, modiilcations, and deficiences in 

 others, that it is impossible for us to avail ourselves of any such diversities. 

 Aristotle endeavoured to estabhsh a distinction by laying it down as a 

 maxim that man has the largest brain of all animals in proportion to the 

 size of his body ; a maxim which has been almost universally received 

 from his own time to the present period. But it has of late years, and 

 upon a more extensive cultivation of comparative anatomy, been found 

 to fail in various instances ; for while the brain of several species of the 

 ape kind bears as large a proportion to the body as that of man, th« brain 

 of several kinds of birds bears a proportion still larger. M. Sommering 

 has carried the comparison through a great diversity of genera and species ; 

 but the fallowing brief table will be sufficient for the present purpose. 

 The weight of the brain to that of the body, forms — 



* For an examination of the general subject of craniolojnr and physiognoitv, see Ser. IIL 

 Lect. XTIf. 



