320 FUNCTIONS AND INSTINCTS. 



author, amongst the Annulosans or Condylopcs. 

 Dr. Von Baer is of opinion that these Entozoa, 

 or worms, reducible to no common type of orga- 

 nization, inhabiting various animals in various 

 parts of their body, together with the Infu- 

 sories and others might be added should be 

 banished from a natural arrangement of animals. 

 He seems also to think, in which I feel disposed 

 to agree with him, that the leading types of animal 

 organization are to be found in its lowest grades. 1 

 As I formerly observed with respect to the In- 

 fusories 2 these appear to be the basis on which 

 God has built the animal kingdom. As some of 

 the species appear connected with the Anneli- 

 dans, I have introduced the Class here, but not 

 as having formed any settled opinion as to its 

 proper division and legitimate station. 



The majority of this Class are, what their 

 name imparts, intestinal worms, or parasites, 

 that have their station within the body of 

 other animals. Some of them, however, do 

 not answer this description, as they are found 

 only amongst aquatic vegetables ; of this kind 

 is a little tribe, which Linne arranged with 

 the leeches, 3 to which they approach by the 

 flukes. 4 The Planaria, in some respects, par- 

 takes more of the nature of a polype than of any 



1 See Zool. Journ. July October, 1828, 260. 



2 See above, p. 148. 3 Hirudo. 

 4 Fasciola. Distoma. 



