SHELLS. 29 



terns and shapes, and yet they are all alike in 

 many respects. 



Teacher. They have undoubtedly all a 

 general resemblance, which enables you at once 

 to determine that they are shells ; but more than 

 this, do you not observe that some are more 

 alike than others ? 



Child. There are some that are very much 

 alike in shape. 



Teacher. Yes, and yet differ in other res- 

 pects ; but is this all that you observe ? 



Child. No, there are some that appear ex- 

 actly alike. 



Teacher. Thus when you look at a collection 

 of shells for the first time, you are struck by 

 their general similarity, and you at once call 

 them all shells. After a little inspection, it 

 will be evident that amongst them, some have a 

 few points qf resemblance, and that others are 

 quite alike in all respects. Thus you begin to 

 perceive that the variety which at first almost 

 bewildered you, is limited by a principle, and 

 whilst your eye is gratified by the diversity, 

 your judgment is satisfied by the order you find 

 preserved. Tell me a similar circumstance in 

 another class of natural objects. 



Child. Flowers afford one. All roses are 

 alike in general appearance, but the Moss Rose 

 is easily distinguished from the China Rose. 



Teacher. The variety exhibited in the works 

 of nature cannot fail* to delight us, and the re- 

 semblances observable in them enable us to 



