148 NATURAL HISTORY. 



case, the great systematist, finding himself confronted 

 with a large series of the lower animals with which 

 his acquaintance, as that of all naturalists of the day, 

 was comparatively imperfect, grouped these together 

 into a single great division, which was necessarily ill 

 denned and imperfectly characterised. To Cuvier is 

 due the recognition of the Articulate Animals as a great 

 primary division, and also the separation of the whole 

 series of the Molluscs from the Linnean Vermes, and 

 their establishment as a second great primary division 

 of Invertebrates. It was left to later naturalists to show 

 that the Cuvierian Radiata was really a miscellaneous 

 and artificial group; and that it could be split up into 

 three great divisions, which may be regarded as equivalent 

 to 'sub-kingdoms' namely, (i) the Echinoderms (sea- 

 urchins and star-fishes); (2) the Coelenterate animals 

 (corals, sea-anemones, jelly-fishes, and zoophytes generally; 

 and (3) the Protozoa (Infusorian animalcules, &c.). 



Not only was the grouping of the animal kingdom 

 adopted by Cuvier much more in accordance with the 

 true relationships of animals than that of Linnaeus, but 

 the principles upon which this grouping was based 

 were also much more philosophical. Linnaeus, as has 

 been seen, in framing his classification, was principally 

 anxious to supply naturalists with a kind of index to 

 the animal kingdom, so constructed that it might be 

 easy to determine the place in his system of any given 

 animal. He therefore based his arrangement upon 

 the presence or absence of certain easily recognisable, 

 for the most part externally visible, characters. Such 

 external and arbitrary characters, chosen principally 



