194 FUNCTIONS OF THE NERVOUS SYSTEM. 



ever, that Man is not unfrequently compelled by the strength of his Emotions 

 to act against his Will. Thus, we see or, hear something ludicrous, which 

 involuntarily produces laughter, although we may have the strongest motives 

 for desiring to restrain it. On the other hand, a loathsome object, which excites 

 the feeling of disgust, produces nausea and even vomiting. Or, again, a violent 

 fright not unfrequently occasions convulsive movements; and these may be 

 brought on, in some excitable states of the nervous system, by Emotions of a less 

 powerful kind ( 298, 299).* 



283. Dr. M. Hall is of opinion that the Spinal system of nerves constitutes 

 the channel of Emotional actions. There is no other evidence for this, how- 

 ever, than the occasional manifestation, in cases of paralysis, of reflex and 

 emotional actions, when voluntary control is lost. Such cases only prove, 

 however, that emotional actions are not volitional ; they are far from proving 

 them to be Spinal. If the essential correspondence between the purely Emo- 

 tional acts of Man, and the Instinctive acts of the lower animals be admitted, 

 we may reasonably localize their centre more satisfactorily, in that chain of 

 ganglionic masses, which only occupies the centre of the base of the brain in 

 Man, but which, in the lower Vertebrata, possesses an aggregate dimension 

 far exceeding that of the Cerebral hemispheres-. We are led to such a locali- 

 zation by a very simple and satisfactory train of reasoning. The actions in 

 question are not simply reflex ; since sensation, and something of the nature 

 of emotion, both involving consciousness, are elements in their performance ; 

 and, moreover, these sensations are rather of the special than of the common 

 character, involving, therefore, the olfactory, optic, and auditory ganglia. No 

 intelligent person can doubt, that, as we descend the scale of being, instinct 

 is gradually superseding reason ; and that in the lowest Vertebrata, the mani- 

 festations of the latter are extremely feeble, nearly all the actions of life being 

 guided by the former. Now on looking at the Encephalon, we perceive a 

 difference in the relative proportions of its principal divisions, so closely cor- 

 responding with these, that it is difficult to imagine them unconnected. In 

 proportion as we descend the scale, we find the Cerebral Hemispheres dimin- 

 ishing in relative size, whilst the Ganglia at the origins of the nerves of special 

 sensation increase to a remarkable degree ; and we cannot, therefore, but con- 



* It is a very interesting question, how far actions at first performed voluntarily by 

 Man, may by habit cease to require an effort of the Will ; being prompted, like the In- 

 stinctive class of movements, by the direct impulse of sensations. Thus we all know 

 that, in walking along an accustomed road, we frequently occupy our minds with some 

 continuous train of thought, and yet our limbs continue to move under us with regular- 

 ity, until we are surprised by finding ourselves at the place of our destination, or perhaps 

 at some other which we had not intended to visit, but to which habit has conducted us. 

 Or we may read aloud for a long time, without having in the least degree comprehended 

 the meaning of the words we have uttered; our attention having been closely engaged 

 by some engrossing thoughts or feelings within. Or a Musician may play a well-known 

 piece of music, whilst carrying on an animated conversation ; the Author has known a 

 skilful performer who could play at sight whilst thus occupied. Now in such a case it 

 would be said by some Metaphysicians (acknowledging, as most do, that the mind can- 

 not will two different things at the same time) that the Volition is in a sort of vibratory 

 condition between the two sets of actions, now prompting one, and now the other. But 

 it would seem much more conformable to the analogy afforded by other psychical phe- 

 nomena, to refer the habitual series of actions to the same division of the Nervous System 

 with the Instinctive; and perhaps the term Automatic may be fairly applied to the whole 

 of this group. It is well known that in cases of severe injury of the brain, in which In- 

 telligence and Will seem completely in abeyance, habitual actions may be often excited. 

 Thus, Dr. Perceval, in his Essay on Habit, mentions the case of a*nuff-taking countess, 

 in whom, when seized with apoplexy, irritation of the nose with a feather produced con- 

 traction of the forefinger and thumb of the right hand ; and Mr. Travers has recorded a 

 similar fact m the case of a boy, who, when apparently insensible from depressed frac- 

 ture of the skull assisted in removing his clothes, preparatorily to the required operation. 



