ANIMAL KINGDOM. 299 



Reproduction here appears to be the greatest where the 

 vital principle is the least distinct. A MoUusque is less 

 tenacious of life indeed than a Polype, but more so than 

 a Vertebrated animal. The lazy tortoise moves after hav- 

 ing been cut in pieces, and the lizard reproduces vei7 

 considerable portions of its body when they may have 

 been amputated or in any way destroyed. It is man, and 

 the more perfect animals in this series, that can the worst 

 sustain wounds; to them a member once lost is irrecover- 

 able. In applying this observation to the Annulose ani- 

 mals, we should from analogy conclude that the Cms- 

 tacea are inferior to Hexapod insects, since the former 

 are observed to be capable of reproducing a lost part, and 

 to the latter it is lost for ever. In this manner a Coleopte- 

 rous or Hymenopterous insect cannot be considered as 

 having its vital principle so much dispersed throughout the 

 common mass ofthebodyasaCrustaceousanimal: inother 

 words, it may be accounted to be more perfectly organized. 

 This last is however an argument on which I would not 

 be understood to lay much stress ; because, as the reader 

 will perceive in the sequel, the reproduction of the feet in 

 Crustacea and Arachnida may be accounted for on the 

 mere ground of the nature of their metamorphosis. 



But the strongest position of M. Latreille remains yet 

 untouched ; namely, that in which he argues from the si- 

 milarity of their organs of circulation and respiration that 

 there must be some immediate connexion between Crus- 

 tacea and those fishes which come the nearest to the Am- 

 phibia. He remarks that if the Batracian reptiles, the Cy- 

 clostomous fishes, and the Crustacea be formed into a series, 

 and the position of their respective branchije be studied, it 

 will be discovered that they gradually separate and arrange 



