698 FUNCTIONS OF THE CER EBRO -SPINAL NERVOUS SYSTEM. 



themselves, of which the Human being is ordinarily regarded as destitute. 1 

 On the other hand, those who have obtained most influence over the under- 

 standings of others, have always been large-brained persons, of strong intel- 

 lectual and volitional powers, whose emotional tendencies have been subor- 

 dinated to the reason and will, and who have devoted their whole energy to 

 the particular objects of their pursuit. It is very different, however, with 

 those who are actuated by what is ordinarily termed genius; and whose 

 influence is rather upon the feelings and intuitions, than upon the under- 

 standings of others. 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, which they 

 do not sufficiently endeavor to control by 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 be held up for imita- 

 tion. In such persons, the general power of the mind being low, the Cere- 

 brum 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; for we not unfrequeutly meet with men possessing large and well- 

 formed heads, whose psychical 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 com- 

 monly found in persons of what has been termed the phlegmatic tempera- 

 ment, in whom the general processes 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. 



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

 the Cerebrum, which may be derived from examination of its Comparative 

 development, we proceed to our other sources of information, Experiment 

 and Pathological phenomena. The electrical excitability of the hemispheres 

 was experimentally demonstrated by Fritsch and Hitzig, 2 who found that 

 on the application of a galvanic stimulus to particular regions of the surface 

 of the hemisphere, certain definite muscular movements occurred on the 

 opposite side of the body, such as flexion, extension, and rotation of the 

 limbs, and also movement of the facial muscles. Their earlier experiments 

 were made on dogs, and the constant currents applied were feeble. The 

 contraction on making the current was greater than that on breaking it. 

 They adduced various reasons against the supposition that the movements 

 were due to mere conduction of the stimulus to -distant centres, amongst the 

 more important of which were the feebleness of the currents employed, the 

 close approximation of the electrodes, the bad conductivity of the brain- 

 substance, the occurrence of contractions on the opposite side of the body, 

 and their non-appearance when the position of the electrodes was slightly 

 altered. In further researches Hitzig 3 believed he was able to establish the 

 existence of a distinct centre for the several movements of the eyes, coincid- 

 ing with a part of the Faeialis centre, and especially that part innervating 

 the protective muscles of the eye. He subsequently 4 found in experiments 

 on monkeys that the anterior cerebral convolution constitutes the true motor 



1 A remarkable instance of this was published some years since: A perfectly 

 idiotic yirl, in Paris having been seduced by sonic miscreant, was delivered of a 

 child without assistance; and it was found that, she had iinatrnl the umbilical cord in 

 two, iu tin' >ame manner as is practiced by the lower animals. It is scarcely to be 

 supposed that she hud any idea of the object of this separation. 



'* Reiehert's An-liiv, 1870, p. 300. 3 Ibid., 1873, p. 397. 



4 Berliner Klin. Woclienschr., 1874, No. 6. 



