PREFACE TO THE FIRST EDITION. 7 



trivial appear those causes which it has been pleased to leave dependent on the will of 

 man ! How astonishing to behold so many fine minds, consuming themselves, so 

 uselessly for their own happiness and that of others, in the pursuit of vain combina- 

 tions, the very traces of which a few years suffice to obliterate ! 



I avow it proudly, these ideas have been always present to my mind, — tlie companions 

 of my labours ; and if I have endeavoured by every means in my power to advance 

 this peaceful study, it is because, in my opinion, it is more capable than any otlier of 

 supplying that want of occupation, which has so largely contributed to the troubles of 

 our age ; — but I must return to my subject. 



There yet remains the task of accounting for the principal changes I have effected 

 in the latest received methods, and to acknowledge the amount of obligation to those 

 naturalists, whose works have furnished or suggested a part of them. 



To anticipate a remark which will naturally occur to many, I must observe that I 

 have neither pretended nor desired to class animals so as to form a single line, or 

 as to mark their relative superiority. I even consider every attempt of this kind im- 

 practicable. Thus, I do not mean that the mammalia or birds which come last, are 

 the most imperfect of their class ; still less do I intend tliat the last of mammalia 

 are more perfect than the first of birds, or the last of moUusks more perfect than the 

 first of the annelides, or zooph3'tes ; even restricting the meaning of this vague word 

 perfect to that of " most completely organized." I regard my divisions and subdivisions 

 as the merely graduated expression of the resemblance of the beings which enter into 

 each of them ; and although in some we obsen'e a sort of passage or gradation from 

 one species into another, which cannot be denied, this disposition is far from being 

 general. The pretended chain of beings, as applied to the whole creation, is but an 

 erroneous application of those partial observations, wliich are only true when confined 

 to the limits within which they were made; and, in my opinion, it has proved more 

 detrimental to the progress of natural history in modern times, than is easy to 

 imagine. 



It is in conformity with these views, that I have established my four principal 

 divisions, which have already been made known in a separate memoir. I still think 

 that it expresses the real relations of animals more exactly than the old arrangement of 

 Vertehruta and Invertehrata, for the simple reason, that the former animals have a much 

 greater mutual resemblance than the latter, and that it was necessar}' to mark this 

 difference in the extent of their relations. 



M. Virey, in an article of the Noiweau Dictionnaire d'Hisfoire Naturelle, had 

 already discerned in part the basis of the division, and principally that which reposes 

 on the nervous system. 



The particular approximation of oviparous Vertebrata, inter se, originated from the 

 curious observations of W. Geoffroy on the composition of bony heads, and from those 

 which I have added to them relative to the rest of the skeleton, and to the muscles. 



In the class of Mammalia, I have brought back the Solipedes to the Paclnjdermata, 

 and have divided the latter into families on a new plan ; the Ruminantia I have placed 

 at the end of the quadrupeds ; and the Manati near the Cetacea. The distribution of 

 the Carnaria I have somewhat altered ; the Oustitis have been wholly separated from 

 the Monkeys, and a sort of parallelism indicated between the Marsvpiata and other 

 digitated quadrupeds, the whole from my own anatomical researches. All that I hav° 



