16 LESSON I. 



with which they select suitable food. This cir- 

 cumstance also proves that they possess the 

 sense of taste. You must now recapitulate all 

 that has been said concerning the mollusca. 

 Whence is the name derived 1 



Child. From mollis, the Latin for soft. 



Teacher. What kind of body have they 1 



Child. Cold, slimy, soft, and fleshy. 



Teacher. Yes ; and another quality you 

 observed when I touched the snail several 

 times. 



Child. That its body is contractile. 



Teacher. And what enabled it so quickly to 

 contract its body, and retreat into its shelter 1 



Child. Its being furnished with muscles. 



Teacher. When you compare these animals 

 with others, in what respect do they appear 

 deficient ? 



Child. They have no bones, the shell acting 

 as a support to their bodies, which are attached 

 to it by muscles. 



Teacher. What envelops the mollusca ? 



Child. A sac or mantle. 



Teacher. Describe the mantle. 



Child. The mantle is full of pores and 

 glands, and is moistened by a slimy exudation 

 sometimes it quite encloses the animal, having 

 only one opening like a purse, sometimes it has 

 expansions at the side, like fins, and sometimes 

 it spreads over the shell. 



Teacher. What are glands ? 



Child. Small lumps containing fluids, which 

 are separated from the blood. 



