2 6 TWO YOUNG NATURALISTS. 



"The vertebrates, to which we ourselves have the 

 honour to belong," added Kene" himself, not wishing 

 to pass for a complete ignoramus, " possess all of them 

 an internal skeleton, of which the most important part 

 is the vertebral column, or spine." 



"All, or nearly all." 



" What ! are there then vertebrates that have no 

 vertebrae?" 



" Only one kind : an unfortunate little fish, the 

 Amphioxus, is in this anomalous condition, as if to 

 prove that all classifications are artificial made, in 

 fact, by learned men for their own convenience, and 

 that in nature the transition from one type to another 

 is never abrupt, but occurs in a gradual manner." 



" As to Mollusca But I am afraid we must not 

 attempt to study them to-day, for want of examples." 



" On the contrary, here are some splendid speci- 

 mens," said Uncle Bob, opening the door of the din- 

 ing-room, and pointing to a pyramid of oysters, with 

 their ponderous shells, heaped upon the table. 



