224 RAMBLES OF A NATURALIST. 



among individuals, and yet we have seen, both in the 

 Syllis and in the Medusae, that this supposed re- 

 semblance does not exist between the offspring and 

 the parents, or even between the former. The purely 

 biological idea of the succession of beings must there- 

 fore in future be substituted for the wholly mor- 

 phological idea of identity of character among them. 

 With these results, which touch upon the funda- 

 mental questions of zoology, we must associate others 

 of a more general nature. For many ages the animal 

 and vegetable kingdoms were, in the eyes of the 

 learned as well as the unlearned, separated by definite 

 limits. At the present day, this is no longer the 

 case. In proportion as attempts were made to define 

 more exactly the pretended differences which, it was 

 conjectured, must, of necessity, exist between these 

 great divisions of animated creation, it was found 

 that one by one they gradually disappeared. At 

 the summit of either kingdom of nature, the na- 

 turalist cannot be deceived as to the animal or vege- 

 table nature of the object he is examining ; but in 

 proportion as he descends, and departs from this 

 highest point in the field of inquiry, new analogies 

 and resemblances are constantly presenting them- 

 selves to his notice, until the moment at length 

 arrives when the most scrupulous examination is 

 insufficient to afford complete certainty. At the 

 extremity of the two series, there exist entire 

 families, for the possession of which botanists and 

 zoologists have contended for ages, and whose am- 

 biguous nature has never yet been determined, not- 

 withstanding the combined efforts of these observers. 



