OF VITAL MOTION. 81 



to be the effects of the same force upon the rich 

 vascular web in muscular tissue. A part of muscular 

 contraction must therefore be consequent upon the 

 abstraction of force from the vessels, and that the rest 

 of -the phenomenon is of a similar character we may 

 argue from the affinity which exists between the 

 fibrous elements of the coats of the vessels and true 

 muscular fibre, an affinity which affords a strong 

 argument in favour of a common law of action in 

 these fibres. 



From these and similar facts it would appear that 

 voluntary muscle is affected by the non-nervous 

 varieties of organic force, in the same manner as the 

 subordinate textures which were previously consi- 

 dered. The presence of the force that is to say 

 determines a state of dilatation in the subject of 

 it; the absence allows the opposite condition of 

 contraction. 



2. Of extra-organic force as the agent in the 

 movements of voluntary muscles. 



In the higher phenomena of muscular action the 

 special powers of the organism have masked and 

 superseded all others, but still we may detect the 

 agency of foreign force, and perceive the sameness of 

 its law of action. 



G 



