148 PHYSICAL EXPRESSION. 



fall in their relative position to the skull which 

 supports them. This is easily observed in cases 

 of palsy of one side of the face, where the position 

 of the features on the two sides is easily compared.* 

 Postures of the face may then in part be due to 

 gravity. As far as I know, the positions of the eyes 

 are not affected by gravity. One of the indications 

 or expressions of a moderate conditions of sleepiness 

 or debility is that the head is not kept erect ; gravity 

 fails to stimulate the muscles put on a slight strain 

 by bending (inclining) the head to one side. 



In looking to the significance, meaning, or direct 

 expression of postures, we must try and determine 

 the causation. Some postures are the result of 

 reflex action. 



If a small object is placed in the hand of a 

 healthy child, a year old, the fingers close on it. 

 This is probably a purely reflex movement. The 

 posture of the hand or fingers which results, being 

 due to reflex action, may be termed a reflex posture, 

 in contradistinction to the so-called spontaneous 

 postures. Examples of reflex postures are seen in 

 contraction of the orbicularis oculi under the 

 influence of light ; in many cases where an object 

 is grasped in the hand without a conscious act on 

 the part of the subject ; in the arm when kept near 

 a part of the trunk that is the seat of some irrita- 

 tion (being tickled). 



Spontaneous postures are those which appear to 

 come about as the result of the intrinsic action of 



* See chap. xi. 



