xii THE AUTHOR'S PREFACES. 



I was necessitated then, — and the task occupied considerable time, — I was com- 

 pelled to make anatomy and zoology, dissection and classification, proceed beforehand ; 

 to seek, in my first remarks on organization, for better principles of distribution ; 

 to employ these, in order to arrive at new remarks ; and in their turn the latter, to 

 carry the principles of distribution to perfection : in fine, to elicit from the mutual 

 reaction of the two sciences upon each other, a system of zoology adapted to serve as 

 an introduction and a guide in anatomical researches, and a body of anatomical doctrine 

 fitted to develope and explain the zoological system. 



The first results of this double labour appeared in 1795, in a special memoir upon a 

 new division of the white-blooded animals. A sketch of their application to genera, 

 and to the division of these into sub-genera, formed the object of my Tableau 

 £ltme)itaire des Animaux, printed in 1798, and I improved this work, with the assistance 

 of M. Dumeril, in the tables annexed to the first volume of my Lemons d' Anatomie 

 Compart^e, in 1800. 



I should, perhaps, have contented myself with perfecting these tables, and proceeded 

 immediately to the publication of my great work on anatomy, if, in the course of my 

 researches, I had not been frequently struck with another defect of the greater number 

 of the general or partial systems of zoology ; I mean, the confusion in which the want 

 of critical precision had left a vast number of species, and even many genera. 



Not only were the classes and orders not sufliciently conformed to the intrinsical 

 nature of animals, to serve conveniently as the basis to a treatise on comparative 

 anatomy, but the genera themselves, though ordinarily better constituted, offered but 

 inadequate resources in their nomenclature, on account of the species not having 

 been arranged under each of them, conformably to their characters. Thus, in placing 

 the Manati in the genus Morse, the Siren in that of the Eels, Gmehn had rendered any 

 general proposition relative to the organization of these genera impossible ; just as by 

 approximating in the same class and in the same order, and placing side by side, the 

 Cuttle and the fresh-water Polypus, he had made it impossible to predicate anything 

 generally of the class and order which comprised such incongruous beings. 



I select tlie above examples from among the most prominent ; but there existed 

 an infinitude of such mistakes, less obvious at the first glance, which occasioned incon- 

 veniences not less real. 



It was not sufficient, then, to have imagined a new distribution of the classes and 

 orders, and to have properly placed the genera ; it was also necessary to examine all 

 the species, in order to be assured that they really belonged to the genera in which 

 till V had been placed. 



1 laving come to this, I found not only species grouped or dispersed contrary to all rea- 

 son, but I remarked that many had not been established in a positive manner, either 

 by the characters which had been assigned to them, or by their figures and descriptions. 



Here one of tliem, ! • means of synonymes, represents several under a single name, 

 and often so ditlVreiic that they should not rank in the same genus : there a single 

 one is doul,lcd. tripk-d. and successively reappears in several sub-genera, genera, and 

 sometimes dillercnt orders. 



What can be said, for example, of the Trichechus manatus of Gmelin, which, under 

 a smglc s,,ecific name, comprehends tliree species and two genera,— two genera differing 

 m almost everj-thing ? By wliat name sliall we speak of the relella. which figures 



