MEMOIR OF CUVIER. ^ 123 



"blood arc fouiul toLc distiil)ntcHl into six classes : moUus/cs, crustaceans, insects, 

 worms, cchinodcrms, and zoophytes. 



Everytbino" was new in tliis distribution ; but everything was at tlie same time 

 so evident that it was generally adopted, and thenceforward the animal kingdom 

 assnuied a new face. Moreover, the precision of the characters on whi(;h each 

 of these classes was founded, the ]j(!rfect conformity of the beings whicii were 

 assend)led under each of them, could not but prove convincing to naturalists; 

 and what doiduh^ss a})pcared to them not less wortli}^ of admiration than these 

 direct and immediate results, was the su(hlen light which tliereby broke on tlie 

 highest points of the science — the grand ideas on tlic subordination of the organs 

 and on the ofllce of this subordination in their employment as characters — those 

 great laws of the animal organizatit)n thus and so early apprehended : that all 

 animals with white blood which have a lieart have also brancliia? or a circum- 

 scribed respiratory organ ; that all those which have no heart have only a 

 trachea ; that wherever the heart and the branchiae exist, the liver exists j that 

 wherever they are wanting the liver is wanting.* 



Assuredly, no one had as yet thrown a glance so comprehensive, so penetrat- 

 ing on the general laws of the organization of animals, and it was easy to fore- 

 see that if he shoitld pursue the investigation of those laws with anything like 

 the same continuity, Cuvier, whose first views had imparted to science so brilliant 

 an impulse, would not be long in extending its boundaries in every direction. 

 He has often recalled since, and even in his last works, this first memoir, from 

 which, in truth, date the germs both of the grand renovation Avhich he effected 

 in zoology and of the greater part of his most fundamental ideas in coinp;irative 

 anatomy. 



Never, indeed, had the domain of a science been so rapidly augmented. With 

 the esce])tion of Aristotle, whose philosophic genius had neglected no part of 

 the animal kingdom, scarcely had any one studied, at any epoch, more than the 

 vertebrate animals alone, at least in a general and thorough manner. The ani- 

 mals with uhite Hood, or, as M. Lamarck has since called them, the animals iviih- 

 Oiit vertebra;, formed in some sort a new animal kingdom, almost unknown to 

 naturalists, and of which M. Cuvier had at once revealed to them as well the 

 diS'erent plans of structm-e as the particular laws to wliich each of these plans 

 is subjected. All these animals — so numerous, so varied in their forms, and the 

 knowledge of which has since so greatly extended the basis of general j)hysi- 

 ology and natural philosophy — were then of scarcely any account to tlie pliysi- 

 ologist and the })hilosopher ; and even long after these great labors of M. Cuvier 

 of which I speak, how man}' systems have we not seen which, pretending to 

 embrace under one sole point of view the entire animal kingdom, have embraced 

 in reality only the vertebrata? So vast was the new route which ho had traced 

 for naturalists, and so dithcult was it found to follow him therein, on account of 

 its very vastness, 



•In this first memoir, then, M. Cuvier had succeeded in finally establishing the 

 true division of animals with while Idood. In a second, taking up sj)ecially 

 one of their classes, that of the mollusks, he laid the loundations of his great 

 work on those animals — a lal)or which occu})ied him for so many years, and 

 which has produced an assemblage of results the most surprising, perhaps, and 

 at least the most essentially new of all modern zoology, as of all modern com- 

 parative anatomy. 



Till then there had been no example of an anatomy so exact and bearing on 

 so great a numl)er of fine and delicate parts. Daulxmton, that model of precis- 

 ion and exactness, had scared}' described with erpial detail more than the skele- 

 ton and the viscera of quadrupeds ; here there was the same attention and a 



* By the liver I ineim a ihtissive and comjitict or<Tan, a conj^lornerate phmd ; in insects tliQ 

 eecreiioMs in effect are accomplished simply by tubes very loug aud slender, which float iu 

 the interior of the body and are lixed only by the tracheae. 



