THE 
ANIMAL KINGDOM. 
PREFACE TO THE FIRST EDITION. 
Having been devoted, from my earliest youth, to the study of comparative anatomy, 
that is to say of the laws of the organization of animals, and of the modifications 
which this organization undergoes in the various species, and having, for nearly thirty 
years past, consecrated to that science every moment of which my duties allowed me 
to dispose, the constant aim of my labours has been to reduce it to general rules, and 
to propositions that should contain their most simple expression. My first essays soon led 
me to perceive that I could only attain this object in proportion as the animals, whose 
structure I should have to elucidate, were arranged in conformity with that structure, 
so that under one single name, of class, order, genus, &c., might be embraced all those 
species which, in their internal as well as exterior conformation, present accordancies 
either more general or more particular. Now this is what the greater number of 
naturalists of that epoch had never sought to effect, and what but few of them could 
have achieved, even had they been willing to try ; since a parallel arrangement presup- 
poses a very extensive knowledge of the structures, of which it ought, in some measure, 
to be the representation. 
It is true that Daubenton and Camper had supplied facts, — that Pallas had indicated 
views ; but the ideas of these well-informed men had not yet exercised upon their 
contemporaries the influence which they merited. The only general catalogue of 
animals then in existence, and the only one we possess even now, — the system of 
Linnaeus, — had just been disfigured by an unfortunate editor, who did not so much as 
! take the trouble to comprehend the principles of that ingenious classifier, and who, 
wherever he found any disorder, seems to have tried to render it more inextricable. 
It is also true that there were very extensive works upon particular classes, which 
had made known a vast number of new species ; but their authors barely con- 
sidered the external relations of those species, and no one had employed himself 
in co-arranging the classes and orders according to their entire structure : the cha- 
racters of several classes remained false or incomplete, even in justly celebrated 
anatomical works ; some of the orders were arbitrary ; and in scarcely any of these 
divisions were the genera approximated conformably to nature. 
B 
