88 



SUMMARY. 



Summary of Pi.ATYUf:i.MiNTHE« anii Nbmathei..mixthes. 



Amongst tlicsu two divisions of worms we have gone into we 



must note several import- 

 ant points. First, their 

 parasitic habits, and the 

 often fatal results of this 

 parasitism ; secondly, the 

 almost universal rule (ex- 

 cept in some Nematodes) 

 of having two distinct 

 hosts during their life- 

 cycle ; thirdly, the extra- 

 ordinary reproduction, 

 often asexual, and the 

 occasional alternation of 

 generations; fourthly, 

 their great vitalitj', not 

 only in the egg, but also 

 in the larval form ; and 

 last, but not least, the 

 great part water plays in 

 their natural history and 

 distribution. In nearly 

 all the worst forms of 

 worms producing animal 

 diseases, the worm passes 

 some part of its life con- 

 nected with water or in 

 water animals ; for in- 

 stances take the Flukes, 

 Palisade - worms, Gape- 

 woruis, Ascarids, Filarias, 

 and even some Cestodes. 

 Thus by paying some at- 



Nimmaii 



Fia. 30. — (K\UREs III.- Horse. 



s with long tails (= MaMi<}"<h-^). (Fiom 

 11.) 



