278 NATURAL HISTORY OF ORGANIZED BODIES. 



establish the affinity or the separation of beings on the most important char- 

 acters. 



Anatomy, in the mean time, came in aid and revealed the interior structuro 

 of animals and plants. It showed that certain organs seem, from their constant 

 occurrence in the series of beings, to have on that account a predominant 

 importance, "while others Avhich are frequently modified, and sometimes Avholly 

 Avanting, appear to be but accessories, and of a secondary- utility. Hence it is 

 that the presence of a vertebral canal containing the s])inal marrovr has furnished 

 the distinctive character of a whole branch of the animal kingdom, that, namely, 

 of the vertcbrata. In this second phase of the evolution of the natural sciences, 

 man no longer confined himself to the role of a spectator of nature. He scru- 

 tinized and compared ; he essayed to form an idea of the general plan of tht) 

 organization of beings. The dry nomenclature had thus given place to a 

 methodical classification. 



When Cuvier appeared, comparative anatomy Avas doubtless already founded. 

 Antiquity itself had learned it from Aristotle ; modern times had Avitnessed its 

 advancement 1)V CI. Perrault and Vicq d'Azyr; but mucli remained to be done 

 in order to comi)lete the classifying of animals according to their anatomical 

 constitution. The branch of the invcrtchrata comprised a multitude of incon- 

 gruous orders, among Avhich new diA'isions Avere of course necessary. The 

 invertebrates Avere divided by CuA'ier into three new branches, the MoUusJcs, 

 the Aiiicidata, and the Zoopliytes. This natural classification, based on com- 

 parative anatomy, borrowed the distinctiA'e characters from the arrangement of 

 the most important organs in the animal : from that of the nervous system. 



It Avas noAV that, combining in a comprehensive synthesis particular facts in 

 order to derive from them general ideas, CuA'ier was enabled to throAv light on 

 some of the laAvs Avhich govern the organized Avorld. Such, for example, is 

 the laAv of suhordincdion cf organs, Avhich teaches us that such or such an organ, 

 Avhen it is present in an animal, implies the presence of other organs Avhich are 

 associated Avith it after a necessary manner. Natural history had thus become 

 a veritable science, agreeably to the definition of Bacon: "Sciences are only 

 facts generalized." Noav, generalization had conducted Cuvier to the expression 

 of laAvs. These, in turn, led him to a remarkable consequence — to the creation 

 of paleontology. It was in conformity Avith his hiAV of the correlation of fonns 

 that he reconstructed the entire skeleton of a fossil animal A\hen possessed of 

 but a fcAV of its remains, and restored for science generations of beings which 

 had long disappeared from the surface of the globe. 



By the side of Cuvier another grand historical figure presents itself in Geoffrey 

 Saint Hilaire, his cotemporary and friend, more recently his scientific adversary, 

 I^reposscssed by his labors in the natural classification of beings, Cuvier had 

 bent his Avhole force to the discovery of the differences Avhich separated them. 

 The genius of Geoffi'oy disposed him rather to comparison ; resemblances 

 attracted him more strongly than differences, and enabled him to detect, in the 

 zoological series, the unitA' of plan amidst the diversity of details. History 

 Avill preserve the remembrance of the memorable conflicts of these illustrious 

 ad\-ersaries, conflicts Avhich powerfully developed tAvo great conceptions in which, 

 at last, there is nothing irreconcilable. From this epoch dates the rise of 

 anatomiccdijlnlosoplnj. 



While zoology Avas establishing itself on foundations really scientific, botany 

 had beeii pursuing a parallel career. As early as the XVIIth century, Pierre Mag- 

 nol attempted to substitute for the ancient nomenclatures a natural classification. 

 He sought, in 16S9, to distinguish plants according to their principal organs — 

 tlie roots, the stems, the ilowers, the seeds. But vegetable anatomy Avas too 

 little advanced to permit a classification based on the constitution of the most 

 important organs of plants. Botany had still to pass through the artificial 

 chv ifications of Tourncfort and Linnaeus before arriving at the more perfect 



