72 OF VITAL MOTION. 



nervous system is rudimentary, than in creatures more 

 elevated in the scale of being, and better furnished 

 with nervous organs. Instead of being necessary to 

 contraction, therefore, it would rather appear that 

 nervous influence is concerned in the counteraction of 

 this state; its office being to induce those transient 

 relaxations which are necessary to that rapidity of 

 muscular action which is distinctive of the higher 

 animals. 



The dictates of comparative anatomy are also sup- 

 ported and elucidated, when we study those phenomena 

 of disease which betoken a suppression of nervous 

 power; for in these cases muscular contraction is a 

 frequent symptom. 



The spasm which is characteristic of ramoUissement 

 of the brain is an important argument against the 

 idea that nervous influence determines a state of 

 muscular contraction by the impartation of a stimulus. 

 In this disease there is atrophy of the cerebral sub- 

 stance, and partial paralysis of the sentient and 

 motive energy ; and therefore the spasm, in so far as 

 it may refer to the nervous system for its cause, must 

 be supposed to be symptomatic of diminished, and not 

 of exalted innervation. It is, indeed, as if man was 

 degraded in the scale of being to a point where his 

 muscular acts became long and energetic as in reptiles 

 ^and for the same reason. 



The ordinary tremulous movements of old age, or 



