368 FUNCTIONS OF THE NERVOUS SYSTEM. 



however, with those who are actuated by what is ordinarily termed genius ; 

 and whose influence is rather upon the feelings, than upon the understandings, 

 of those around them. Such persons are often very deficient in the power of 

 even comprehending the ordinary affairs of life : and still more commonly, 

 they show an extreme want of judgment in the management of them, being 

 under the immediate influence of their passions and emotions, and not having 

 brought these under the control of their intelligent will. The life of a genius, 

 whether his bent be towards poetry, music, painting, or pursuits of a more 

 material character, is seldom one which can he held up for imitation. In 

 such persons, the general power of the mind being low, the Cerebrum is not 

 usually found of any great size. The mere comparative size of the Cerebrum, 

 however, affords no accurate measure of the amount of mental power; we not 

 unfrequently meet with men possessing large and well-formed heads, whilst 

 their physical capability is not greater than that of others, the dimensions of 

 whose crania have the same general proportion, but are of much less absolute 

 size. Large brains, with deficient activity, are commonly found in persons of 

 what has been termed the phlegmatic temperament, in whom the general pro- 

 cesses of life seem in a torpid and indolent state ; whilst small brains and great 

 activity, betoken what are known as the sanguine and nervous temperaments. 

 These distinctions come to be very important, where we proceed further in 

 our inquiries, and attempt to determine the particular modes of development 

 of the Brain, which coincide with certain manifestations of the mind. 



485. Having now inquired into the evidence of the general functions of the 

 Cerebrum, which may be derived from examination of its Comparative deve- 

 lopment, we proceed to our other sources of information ; Experiment, and 

 Pathological phenomena. From neither of these, however, is much informa- 

 tion to be derived. The effects of the entire removal of the Cerebral Hemi- 

 spheres have been already stated ( 435). So far as any inferences can be 

 safely drawn from them, they fully bear out the conclusion, that the Cerebrum 

 is the organ of Intelligence ; since the animals which have suffered this muti- 

 lation appear to be constantly plunged in a profound sleep, from which no 

 irritation ever seems able to arouse them into full activity. It may even be 

 argued, that the phenomena which they exhibit do not imply the persistence 

 of consciousness ; and that this also must be regarded as the attribute of the 

 Cerebral hemispheres, being destroyed by their ablation. But a careful ana- 

 lysis of them seems to show, that sensibility still exists, although it is much 

 deadened ; for in no other way can we legitimately explain the efforts made 

 by the animals to balance themselves and maintain their position, which are of 

 a much higher character than the mere reflex movements exhibited by the 

 same animals after the removal of the entire Encephalon, and which can 

 scarcely be explained without attributing to them a degree of sensation. That 

 their sensibility should be greatly blunted, however, is to be anticipated from 

 the fact, that it is almost impossible to remove the Hemispheres, without doing 

 great injury to the other ganglionic centres, especially to the Thalami Optici 

 and Corpora Striata ; which, if the preceding views be correct, form a most 

 important part of the Sensori-Motor apparatus, and which, in the experiments 

 referred to, appear to have been generally removed with the Cerebral Hemi- 

 spheres. The entire and permanent removal of all vascular pressure, top, 

 which is consequent upon the laying-open of the cranial cavity, is another 

 source of permanent disturbance in the functions of the parts which are left. 

 So far as they go, therefore, the results of such experiments confirm the de- 

 ductions drawn from Comparative Anatomy, in regard to the general functions 

 of the Cerebrum ; but we must be careful not to infer too much from them, as 

 to the extent to which the animal functions are brought to a close by the 

 operation in question. In the most recent experiments, those of MM. Bouil- 



