PREFACE TO THE FIRST EDITION. Kix 
In some parts, one of the species, by means of synonymes, is made to 
represent, under a single name, a great number, which are so different 
from each other as to be incapable of being placed in the same genus; in 
others, a single species is doubled, and trebled, and appears again and 
again successively in divers subgenera, genera, and even sometimes in 
various orders. 
What shall we say, for instance, of the Trichechus Manatus of Gmelin, 
which in one single specific name comprises three species and two ge- 
nera; two genera, differing in almost every thing! By what name shall 
we speak of the Velella, which figures there twice among the Medusa, 
and once among the Holothurie? How are we to bring together the 
Biphore; some of which are called there Dagyse, the greater number 
Salpe, and several placed among the Holothurie? 
Thus, then, in order completely to attain the object, it was not sufficient 
to review the species—it was necessary to review even their synonymes, 
or, in other words, it was indispensable to reconstruct the system of 
animals. 
Such an enterprise, from the prodigious development of the science in 
late years, could not have been executed completely by any one individual, 
even supposing him to have no other employment, and to live the longest 
possible term of years. Had I been constrained to depend upon myself 
alone, I should not have been able to prepare even the simple sketch I 
now give; but the resources of my position seemed to me to supply what 
I wanted both of time and talent. Living in the midst of so many able 
naturalists—drawing from their works as fast as they appeared—enjoying 
the use of their collections as freely as themselves—and having formed a 
very considerable one myself especially appropriated to my object, a great 
portion of my labour consisted merely in the employment of so many rich 
materials. It was not possible, for instance, that much remained for me 
to do on shells studied by M. de Lamarck, or on quadrupeds described by 
M. Geoffroy. The numerous and new affinities observed by M. de 
Lacépéde were so many traits for my system of fishes. Among so many 
beautiful birds, collected from all parts of the world, M. Le Vaillant per- 
ceived details of organization, which I immediately adapted to my plan. 
My own researches, employed and multiplied by other naturalists, yielded 
those fruits to me which, in my hands alone, they would not all have 
produced. Thus, by examining, in the cabinet I have formed, the anato- 
mical preparations on which I designed to found my division of reptiles. 
M. de Blainville and M. Oppel anticipated (and perhaps better than I 
could have done) results of which as yet I had but a glimpse, &c. &c. 
These reflections encouraged me; and I resolved on prefixing to my 
Treatise on Comparative Anatomy, a sort of abridged systematic table 
c 2 
