OF VITAL MOTION. 63 



1. Of intra-organic force as the agent in these 

 movements. 



(a.) Of the nervons influence as an agent. 



In a state of fear, when the blanched skin, 

 the faltering heart, and the occurrence of fainting, 

 show how greatly the supply of nervous force has 

 been repressed, the condition of the organic muscles 

 is one of contraction. The pallor of the countenance 

 and the smallness of the pulse is a sufficient proof that 

 this is the case in the fibrous tissues which enter into 

 the walls of the vessels. In parts, also, where the 

 muscular fibre is more developed, as in the coats of 

 the several visceral cavities, the result is the same ; 

 and thus, during the continuance of fear, there is a 

 tendency to contract and expel their contents a fact 

 which is equally apparent in the alimentary canal, in 

 the bladder, and in the uterus. In the first instance, it 

 may be supposed that fear operates by inducing a 

 state of paralysis in a sphincter muscle ; but in the 

 bladder and uterus no doubt of this nature can exist, 

 inasmuch as the openings of these organs are desti- 

 tute of sphincter fibres. Moreover, in the case of 

 the alimentary canal, it must be observed that the 

 tendency to evacuation, under the operation of fear, 

 involves a powerful and sudden contraction of the 

 coats ; for the mere paralysis of the outlet, which is 



