OF THE EXTERIOR MUSCLES. 451 



which compensates, and much more than compensates, the loss 

 of power; without mentioning the form and freedom of the 

 limbs, which could not take place with any other insertion, 

 or any other direction of the muscles with relation to the 

 bones. 



725. The muscle is the seat and the immediate organ of 

 contraction, just as the teguments and the organs of sense, 

 which form part of them, are the seat of impression. But just 

 as sensation takes place only, in so far as the impression is 

 propagated by the nerves to the nervous centre, so is it from 

 the nervous centre that volition is propagated, by the nerves, 

 to the muscle, for setting it in motion. In both cases, there 

 is, moreover, something that is entirely incomprehensible; this 

 is, the manner in which the being, the self, (moi) acquires the 

 knowledge of the sensation, and also the manner in which it 

 determines the volition. This is not the proper place for exa- 

 mining the yet unsolved question of the reciprocal action of 

 the organism and the self (moi}. 



Be this as it may, the volition proceeds from the nervous 

 centre, is propagated by the nerves, and self induces the con- 

 traction of the external muscles. If the nerve be cut or inter- 

 rupted by a tight ligature, &c. the muscle, still irritable, no 

 longer contracts voluntarily. In the following chapter will 

 be seen what is the precise, or, at least, probable, seat, in the 

 nervous system, of the organic principle of the voluntary 

 motions. 



726. The effects of the contraction of the exterior muscles 

 are to determine the attitudes and motions of the body, by 

 acting upon the skeleton ; to move the skin and organs of 

 sense; to produce the voice, speech, and gesture; and, lastly, 

 to subserve, in a more or less necessary, but always auxiliary, 

 manner, the vegetative functions. 



727. It has already been seen that the straight muscles, in 

 contracting, draw one of their extremities, or both, nearer to 

 the centre, according as one of the points of attachment only 

 is moveable, or as they are both so; and that the circular mus- 

 cles, in contracting, narrow the orifices or canals which they 

 form. The curved muscles become straight when they con- 



