NATURAL THEOLOGY. 85 



[The reader will not be easily convinced that the mass of flesh, 

 with which he is familiar, is easily and almost spontaneously di- 

 vided into distinct muscles. This figure represents a muscle. C 

 is tlie belly of the muscle; A and B the tendons: A being the 

 tendinous origin, as it is termed, attached to a fixed point of bone; 

 B the tendinous insertion, being attached to a part movable by 

 the contraction of the muscle. The belly, C, consists of fibres, 

 which are possessed of the power of contraction or irritability, and 

 through the operation of which the various motions of the body 

 are performed. We shall prescHtly have to remark on the direo 

 tion of these fibres.] 



For instance: the principle of muscular motion, 

 viz., upon what cause the swelling of the belly of 

 the muscle, and consequent contraction of its ten- 

 dons, either by an act of the will, or by involun- 

 tary irritation, depends, is wholly unknown to us. 

 The substance employed, whether it be fluid, 

 gaseous, elastic, electrical, or none of these, or 

 nothing resembling these, is also unknown to us : 



duly estimate the power which regulates the secretions and ab- 

 sorption — could we fully understand the relations of this organ, 

 either with the economy of the body within, or the constitution of 

 the atmosphere without — we should have no occasion to draw 

 our argument, for the twentieth time, from the structure of the eye 

 or the ear. Were we to take one cell of the millions of that sub. 

 stance which, intervening between the more solid textures of the 

 frame, gives elasticity to the whole, and permits circulation and 

 muscular action, and all the various movements of the body, we 

 should have in that one cell as much reason for wonder at the per- 

 fection of the contrivance, as in any joint of the limb. 



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