ANIMAL KINGDOM. 293 



ticulated animals ; and, as if to disprove the assertion com- 

 pletely, M. Savigny's observations teach us that the most 

 complicated in organization of the Annelides are not those 

 M^hich come nearest to the Vertebrata, but on the con- 

 trary are the Nereidce, which come nearest to the Myria- 

 poda. Had it been first shown that the descending scale 

 in the perfection of organization is regular from M an to 

 the Infusoria, the truth of the preceding assertion could not 

 have been called in question, because then the most sim- 

 ple vertebrated structure would lead to the most complex 

 unvertebrated animal, and so on ; but what naturalist is 

 there in this age who can get rid of the difficulty in this 

 manner ? The only argument that I am acquainted Avith, 

 as having been adduced to prove the junction of the most 

 complex Annidosa with the Vertebrata, is that the former 

 are gifted with vision. But it so happens that the lowest 

 of Vertebrata, such as Ammocetus and Myxine, to which 

 they are thus united, are deprived by their construction of 

 this power 5 and moreover the eyes of the Annulosa are to- 

 tally different in formation from those of the Vertebrata. 

 For any argument therefore drawn from the eyes in favour 

 of this affinity to be vaUd, it is manifestly necessary that the 

 Vertebrated and Unvertebrated animals brought together 

 should possess eyes constructed on similar principles. 

 Now this is the case, as we have seen, with the Cephalo- 

 poda and Chelonian Reptiles, but not with the Crustacea 

 and Cyclostomous Fishes. Indeed, as to the affinity which 

 is stated to exist between these last, it is sufficient for any 

 person to look at a Lamprey and a Pagurus, which are 

 mentioned as the most favourable examples of each group, 

 being both endowed with sight, and to ask himself — Iji 

 how many points do they agree ? 



