32 LIFE IN NATURE. 



idea of the living body. In respect to one of its 

 chief characteristics, the vital organism ceases to be 

 contrasted with the rest of nature, and becomes to 

 us an example of universal and familiar laws. One 

 form of force acting as a resistance to another, and 

 so accumulating a "store of power, which operates 

 on a structure adapted to direct it to given ends; 

 this is the plan on which the animal creation is con- 

 structed. It is the same plan that we adopt when 

 we seek to store up force, and direct it for our own 

 purposes. We imitate herein the Creator ; humbly, 

 indeed, and with an infinite inferiority of wisdom 

 and of power. But the principle is the same. 



And some otherwise mysterious "properties" of 

 living organs lose their mystery. The " con- 

 tractility " of muscular fibre, and the " sensibility " 

 of the nerves and brain, are seen to be, not mere 

 inexplicable endowments, but names applied to the 

 effect of their known tendency to undergo chemical 

 change. Given the tendency to decompose, and the 

 anatomical structure of the parts, and there must 

 be a power to contract in muscle, and to originate 

 the nervous in brain. 



