MUSCULAR POWER. 



95 



done by the adductor muscle, it would require, from 

 the exertion demanded, a great expenditure of vital 

 force. The economy of means, so apparent in the 

 works of God, is therefore displayed, in uniting with 

 the muscle an elastic ligament, which allows the valves 

 to separate only to a proper distance. 



Even when the mollusk 

 dies, and these muscles 

 cease to act, the elastic 

 ligament of the hinge does 

 not lose its property ; and 

 hence the shell opens, leav- 

 ing the body of the tenant 

 to be devoured by small e 

 Crustacea and other ani- 

 mals, which soon clear it i 

 away. The annexed dia- 

 gram will serve to show 

 the parts to which we have 

 previously alluded, as seen 

 in one of the mactra, of 

 which one valve of the 

 shell is removed with all 

 its mantle, that of the 

 other valve being left, a. 



The Mactra. 



