146 PHYSICAL EXPRESSION. 



are usually free to be stimulated to contraction by 

 slight causes. The capacity of the face for expres- 

 sion exceeds that of any other part of the body. 

 The mobility of the face varies greatly, and there 

 are circumstances under which the facial muscles 

 are not free for the expressions of emotion, as when 

 eating, and when a strong light causes spasmodic 

 contraction of the orbicular muscles of the eyes. 



Postures of the body may be due to organic con- 

 ditions ; they may be due to conditions of the 

 organs, and not express the simple action of the 

 nerve-mechanism. Thus, in spasmodic asthma, the 

 patient, if lying in bed at the commencement of 

 the seizure, is obliged at once to rise up, and he sits 

 leaning forward, with his knees drawn up, his elbows 

 011 his knees, and his head supported by his hands, 

 labouring for his breath. Various postures are 

 assumed to facilitate respiration ; the patient stands 

 erect, with his head thrown backwards, seizing 

 some object to give greater vigour to his efforts, or 

 he leans the head forward on his hands. Such 

 postures are assumed to enable the respiratory 

 muscles to act with greater mechanical advantage. 

 In heart-disease the patient is often unable to lie 

 down, and sits in bed, or in his chair, supported by 

 pillows. Sir Charles Bell * draws attention to pos- 

 tures resulting from organic conditions in his 

 criticism upon the Dying Gladiator (see p. 303). 



Gravity is often a factor of great potency in 

 producing postures of the body. All living bodies 

 are under the influence of the same laws of gravity 

 * Op. ctt., p. 194. 



