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Show viii PHEFACE TO THE FIRST EDITION. ciples of that ingenious methodist, and who, wherever he found any disorder, seems to have tried to render it more in. extricable. It is also true, that there were very extensive works upon particular classes, which had made known a great number of new species; but their authors merely considered the external relations of those species, and no one had employed himself in arranging the classes and orders from the ensemble of the structure ; the characters of several classes remained false or incomplete even in justly celebrated works of anatomy; some of the orders were arbitrary, and in scarcely any of these divisions were the genera placed conformably to nature. I was compelled then, and the task occupied a considerable period of time, I was compelled to make anatomy and zoology, dissection and classification, the pioneers of my steps ; to search for better principles of distribution in my first remarks on or· ganization-to employ them in order to arrive at new ones, and to render the distribution perfect-in fine, from this mu· tual reaction of the two sciences, to elicit a system of zoology that might serve as an introduction and a guide in anatomical investigations, and as 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 their division in subgenera was the object of' my elementary "Tableau Elementaire des Animaux," printed in 1798, which, in conjunction with M. Dumeril, I improved, in the tables annexed to the first volumes of my "Legons d' Anatomic Comparee" 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 acumen has left a great number of species, and even several genera. PREFACE TO THE FIRST EDITION. ix The classes and orders were not only not sufficiently conformed to the intimate nature of animals to serve conveniently as a basis to a treatise on comparative anatomy, but the genera themselves, although mostly better constituted, presented but inadequate resources, on account of the species not having been arranged under each of them, in conformity with these characters. Thus in placing the Sea-cow (Mana· tus, Cuv.) in the genus Morse (Trichechus, Lin.), the Siren in that of the Eels, Gmelin had rendered any general proposition relative to the organization of these two genera imposs. ible, just as by approximating to the same class the sa)lle order, and placing side by side the Sepia and the freshwater Polypus, he had made it impossible to say any thing in general on the class and order which embraced such different beings. The examples above cited are selected from the most striking of these errors ; but there existed an infinitude of them, less sensible at the first glance, which presented difficulties not less real. It was not enough then to have imagined a new arrange· ment of classes and orders, and to have properly placed the genera there; it was also necessary to examine all the species in order to be assured, whether they really belonged to the genera in which they had been placed. Having come to this, I found species not only grouped or dispersed, against all semblance of reason, but I remarked that several had not been positively determined; neither by the characters assigned to them, nor by their figures and descriptions. . Here, one of them, by means of synonymes, represents several in one single name, and often so different from each other that they should not be placed in the same genus; there, a single one is doubled, trebled, and successively reappears in several subgenera, genera, and sometimes in different orders. What shall we say, for instance, of the Trichechus manatus of Gmelin, which in one single speCific name comprises three species and two genera ; two genera, differing in almost · VoL. 1.-(2) |