MOLLUSCA. 29 



are destitute of bones. They have not red warm 

 blood, but a white cold fluid circulates through 

 their frames in vessels issuing from the heart. 

 They have nerves connected with their different 

 organs. They are divided into two classes. 

 The first, mollusca cephala, have a distinct 

 head, bearing lips or jaws, and are furnished 

 with eyes and tentacula. The second, mollusca 

 acephala, have a more simple organization ; 

 they have no distinct head, and are destitute of 

 jaws and other hard parts of a mouth ; they 

 inhabit shells formed of two pieces. 



LESSON IV. 



(Shells.) 



Teacher. Well, did you find the study of the 

 mollusca as uninteresting and unprofitable as 

 you expected it to be ? 



Child. Oh, no, we have, on the contrary, 

 learnt much that has interested and surprised us. 



Teacher. And what useful lesson may you 

 apply to yourselves from the mistake you first 

 made? 



Child. Not to look upon any of the works of 

 God with indifference or contempt, but to feel 

 convinced that if they fail to excite our admira- 

 tion, it is on account of our ignorance. 



Teacher. The more you study Natural 

 History, the more you will be inclined to 

 acknowledge this truth. Now I wish you to 

 3* 



