448 > THE ANIMAL FUNCTIONS. [ch. v. 



some body applied to the nerves. Whence, therefore, it is 

 manifest, that those movements ought alone to be termed 

 animal which depend upon the untrammelled control of the 

 soul, and which it produces or restrains by its own free will; 

 on the other hand, those which in no degree depend on the 

 will, but are performed when the mind is unconscious or un- 

 willing, cannot be termed animal, but are purely mechanical 

 and automatic. 



Observation teaches, that there are some muscles in the 

 human body over which the mind has no control whatever, 

 and the movements of which are purely automatic during the 

 whole of Ufe; these are the heart [the ventricles], the auricles, 

 oesophagus, stomach, and intestinal canal; with these may be 

 mentioned the motion of the iris. There are other muscles 

 which are ordinarily subject to the control of the will, and 

 for this reason are termed voluntary, such as the muscles of 

 the limbs, trunk, head, face, eyes, tongue, genitals, and the 

 sphincter of the anus and urinary bladder. It sometimes 

 happens, however, that all these muscles renounce the authority 

 of the miud, and while it is either unconscious or unwilling, are 

 violently agitated by some preternatural mechanical stimulus, 

 as is seen in hysterical, epileptic, or infantile convulsions, or 

 in those affected with St. Vitus^s dance; and these movements, 

 although performed by muscles designated voluntary, can only 

 be termed automatic. In the foetus in utero and in the newly- 

 born these muscles are not moved voluntarily, but for the most 

 part automatically, for at that age the cerebrum is not as yet 

 capable of thought, until the organs of the faculty of thought 

 being gradually evolved, the mind learns to think, and to use 

 the muscles subjected to its control. The raising of the hand 

 and the application of it to the head in apoplexy belong also 

 to the class of automatic movements, also the turning of the 

 body in sleep, and partly even somnambulism itself, which, 

 however, it would seem is partly also to be ascribed to obscure 

 sensations and vohtions which the mind instantly forgets. In 

 the third place, there are muscles which continually act in- 

 dependently of the will, being excited thereto by a mechanical 

 stimulus only, but over which the mind possesses voluntary 

 command, and can at will accelerate, or retard, or entirely stop 

 their movements for a time; the action of these is termed 



