MOLLUSCA. 23 



Teacher. They cannot indeed go in search 

 of it, but the continued motion of the waves, or 

 the flowing of the tide, brings a fresh supply of 

 water swarming with the little animals upon 

 which they subsist, and some increase the rapid- 

 ity of this supply, by forming currents in the sea. 



Child. What very clever contrivers these 

 animals seem to be. 



Teacher. Yes, and your remark leads me to 

 an important consideration, to which I wish to 

 direct your attention. How do these little ani- 

 mals know that it is well for them to attach 

 themselves to other substances. How have they 

 learned to form the vacuum, or weave the silken 

 filaments 1 



Child. Is it not instinct that directs them ? 



Teacher. Yes, but can you tell me what in- 

 stinct is ? 



Child. It is something that guides animals. 



Teacher. Is man taught in the same way 1 



Child. No, we have reason, and can think 

 about what we do. 



Teacher. Well, let us consider a little the 

 difference between that which directs man, and 

 that which guides other animals. Suppose a 

 child were to see a fire for the first time : not 

 knowing its nature, he might perhaps put his 

 finger into it. Would he do so, do you think, a 

 second time? 



Child. No, he would recollect the conse- 

 quences of having done so before. 



Teacher. He would have learned then from his 

 own experience ; but is all knowledge obtained 



