PHYSICAL EXPEESSION. 



change, but of an organism capable of resisting 

 changes. Retentiveness indicated by reflex action 

 may be seen in the infant at birth. The fact of 

 placing an object between its lips excites the move- 

 meats of sucking ; this is a reflex action, and per- 

 sists as long as the individual is an infant. When 

 the infant becomes a man, this reflex is more or less 

 weakened or lost; the mechanism connected with 

 sucking is not retained in the same condition 

 through life. We see, then, that in this particular 

 mechanism retentiveness is only temporary. 



Movement, as an outcome of action in an animal, 

 is the result of some force, internal (as nutrition) or 

 external, acting upon the animal. The study of the 

 correlation of forces justifies this assumption that 

 visible movement, as the outcome of an organism, 

 expresses either force afferent to the subject, or the 

 result of changes occurring in it changes which are 

 conveniently termed vital action or nutrition. As 

 examples showing movements expressive of nutri- 

 tion in the organism, the following may be cited. 

 Mechanical exercise in man, such as carrying a 

 weight, has been shown by physiologists to be due 

 to changes in the body, and the movements of the 

 man are an expression of the internal changes. A 

 child in perfect physical health is frisky, plays, 

 runs about, and chatters incessantly till he is tired ; 

 the movements indicate the perfect physical health 

 of the subject, because they are the outcome of the 

 perfect nutrition of the organism. If the nutrition 

 of the body at large is low, as the result of deficient 

 or improper food, or disease of some organ, the 



