REFLEX PROCESSES 577 



and how could they be regulated meantime? The regulative reflexes owe 

 their existence to the native organization of the nervous system. Among the 

 many efferent nerves which may be excited by a single afferent nerve there 

 are some to which the impulse is transferred more readily than to others. 

 This naturally suggests that the anatomical connections in such cases are 

 simpler, possibly shorter, than in others. 



In his researches on the conditions influencing secretion in certain digest- 

 ive glands Pawlow's attention was drawn to one circumstance which is of 

 the utmost importance for our comprehension of the reflex mechanisms. We 

 refer to the psychical influence over certain glands, already mentioned at 

 page 263. When the experiment animal had no desire for food stimulation 

 of the mucous membrane of the mouth produced no secretion of gastric juice. 

 The appetite therefore brings about a predisposition in certain portions of 

 the nervous system which constitutes an indispensable condition for the reflex 

 outpouring of gastric juice. In fact, appetite itself, or the mere sight of 

 food, can evoke the secretion. We meet with similar phenomena in other 

 portions of the body e. g., alterations of the heart beat under the influence 

 of emotions, blushing, weeping, the involuntary evacuation of urine and faeces 

 induced by certain psychical states, vomiting caused by disagreeable thoughts, 

 and many more. Hence, while not under the direct control of the will the 

 reflex processes are closely associated in manifold ways with states of the mind. 



Many new reflexes are formed in the course of life, that is to say, move- 

 ments which originally were executed under the control of the will become 

 automatic by practice e. g., standing, walking, piano playing, and the like. 



When a person stumbles over a stone, the purposive movements by which 

 he saves himself from a fall are pure reflexes, as we know from the fact that 

 very often the danger is apperceived only when it is all over. If in such 

 cases' the appropriate movements had to be made voluntarily, very often the 

 body would suffer injury before the mishap could be prevented. Another 

 purpose of reflex movements therefore is to protect the body from external 

 injuries. 



Reflexes play no small part also in personal culture. Good carriage of the 

 body, for example, is nothing more than the result of practice of many muscular 

 movements originally performed painstakingly, until they became purely reflex 

 in character. The general conduct of a cultivated man in his intercourse with 

 his fellow-men is also largely a matter of reflex action. While much in this 

 realm is purely conventional, even this can only be acquired, so as to be invari- 

 ably performed, by practice. 



C. INHIBITION OF REFLEXES 



If it is highly important so to impress certain movements on the nervous 

 system that they will be performed more or less reflexly, it is none the less 

 important to suppress certain others which may be unpleasant or otherwise 

 undesirable. Many such acts are pure reflexes either inherited or acquired 

 by bad training. Such, e. g., are weeping and crying out under pain. A 

 person can learn to suppress this reflex, just as a child can be taught not 

 to cry when everything does not go to its liking. Many facial expressions 



