PREFACE TO TUE FIKST EDITION. XXV 
parate Memoir. I still think it expresses the real relations of animals 
more exactly than the old arrangement of Vertebrata and Invertebrata, 
and for the reason that the former animals have a much greater re- 
semblance to each other than the latter bear to each other, and that it 
was necessary to mark this difference in the extent of their relations. 
M. Virey, in an article of the ‘‘ Nouveau Dictionnaire d’Histoire Na- 
turelle,” had already discovered a part of the basis of this division, and 
principally that which depends on the nervous system. 
The particular approximation mutually between the Oviparous Verte- 
brata originated in the curious observations of M. Geoffroy on the com- 
position of bony heads; and trom those 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 
Pachydermata, and have divided the latter into families, in conformity 
with new views; the Ruminaniia I have placed after the Quadrupeds, 
and the Sea-cow near the Cetacea. The arrangement of the Carnaria I 
have somewhat altered—the Ouisiitiss have been wholly separated from 
the Monkeys, and a sort of parallelism between the pouched animals and 
other digitated Mammalia indicated; the whole from my own anatomical 
researches. All that I have given on the Quadrumana and the Bats is 
based on the recent and profound labours of my friend and colleague, 
M. Geoffroy de Saint-Hilaire. The researches of my brother, M. Fre- 
derick Cuvier, on the teeth of the Carnaria and the Rodentia, have 
proved highly useful to me in forming the subgenera of these two orders. 
Notwithstanding the genera of the late M. Illiger are but the results of 
these same researches, and those of some foreign naturalists, I have 
adopted his names whenever my subgenera could be placed in his genera. 
I have also adopted M. de Lacépede’s excellent divisions of this descrip- 
tion; but the characters of all the divisions and all the indications of 
species have been taken from nature, either in the Cabinet of Anatomy, or 
the galleries of the Museum. 
The same plan was pursued with respect to the Birds. I have exa- 
mined with the greatest care and attention more than four thousand indi- 
viduals in the Museum; I arranged them agreeably to my views in the 
public gallery more than five years ago, and all that is said of this class 
has been drawn from that source. Thus, any resemblance which my 
subdivisions may bear to some recent descriptions is on my side purely 
accidental*. 
* [Note added by the Author to this Preface in the Second Edition.—ENG. Ep. ] 
This observation not having been sufficiently understood abroad, I am compelled to 
repeat it here, and openly to declare a fact witnessed by thousands in Paris—it is 
this, that all the birds in the public gallery of the Museum were named and arranged 
according to my system in 1811. Even such of my subdivisions as I had not yet 
named were marked by particular signs. ‘I'his is my date. Independently of this, 
