FUNCTIONS OF THE CEREBRUM. 367 



well known to those who have had the opportunity of observing their habits : 

 and it is interesting to remark, that their surface occasionally presents an ap- 

 pearance of rudimentary convolutions. 



483. Comparative Anatomy, then, fully bears out the general doctrine, that 

 the Cerebrum constitutes the organ ofvlntelligence, as distinguished from those 

 mere Instincts, by which many of the lower animals seem to be almost en- 

 tirely guided. By Intelligence, we do not mean, however, the reasoning 

 faculties only; but the combination of those powers which are of an educable 

 character, and which become the springs of voluntary action, in varying pro- 

 portions in different animals of the same tribe; as distinguished from those, 

 which have more immediate relation to the wants of the corporeal system, 

 and which are automatic and invariable in the several individuals of the same 

 species. This definition does not leave out of view the operation of the Pas- 

 sions, Feelings, and Emotions; which are all but modifications of Instinctive 

 Propensities, to which different names are assigned. The true character of 

 these, however, can only be understood, by studying the mode of their action 

 on the bodily system. This action is of two kinds; the one direct, irrational 

 and involuntary ; the other indirect, rational, and voluntary. In the former, 

 the action is the immediate result of the Emotion, following closely upon the 

 Sensation which excited it, and consequently belongs to the Consensual group 

 already discussed (Sect. 5) ; it is executed without any consciousness of the 

 purpose to be answered by it; and the power of the Will is only exerted to direct 

 or restrain it. In the latter, as will be presently shown ( 494), the action 

 is but remotely the result of the Emotion, being altogether of the Intelligent 

 class ; it is executed with a view to a distinct purpose, which has been deter- 

 mined on by the reasoning powers, and of which, therefore, the mind is fully 

 conscious; and it is purely an act of the Will, however strongly the Emotions 

 may have acted in supplying motives to it and exciting the intellectual powers 

 to action. 



484. The general inferences drawn from Comparative Anatomy, are borne 

 out by observation of the Human species. When the Cerebrum is fully 

 developed, it offers innumerable diversities of form and size, among various 

 individuals ; and there are as many diversities of character. It may be doubted 

 if two individuals were ever exactly alike in this respect. That a Cerebrum 

 which is greatly under the average size, is incapable of performing its proper 

 functions, and that the possessor of it must necessarily be more or less idiotic, 

 there can be no reasonable doubt. On the other hand, that a large well-de- 

 veloped Cerebrum is found to exist in persons, who have made themselves con- 

 spicuous in the world by their attainments or their achievements, may be stated 

 as a proposition of equal generality. In these opposite cases, we witness most 

 distinctly the antagonism between the Instinctive and Voluntary powers. Those 

 unfortunate beings, in whom the Cerebrum is but little developed, are guided al- 

 most solely by their instinctive tendencies ; which frequently manifest them- 

 selves with a degree of strength that would not have been supposed to exist; 

 and occasionally new instincts present themselves, of which the Human being 

 is ordinarily regarded as destitute.* On the other hand, those who have obtained 

 most influence over the understandings of others, have always been themselves 

 persons of strong intellectual and volitional powers ; in whom the instinctive 

 tendencies have been subordinate to the reason and will, and who have given 

 their whole energy to the particular object of their pursuit. It is very different, 



* A remarkable instance of this has been recently published. A perfectly idiotic girl, in 

 Paris, having been seduced by some miscreant, was delivered of a child without assistance. 

 It was found that she had gnawed the umbilical cord in two, in the same manner as is prac- 

 tised by the lower animals. It is scarcely to be supposed that she had any idea of the object 

 of this separation. 



