mammalia of eocene peuiod. 
»7 
It appears that the animal kingdom was thus 
early established, on the same general prin- 
eiples that now prevail ; not only did the four 
piesent Classes of Vertebrata exist ; and among 
Mammalia, the Orders Pachydermata, Carui- 
'^ora, Rodentia, and Marsupialia ; but many of 
the genera also, into which living families are 
distributed, were associated together in the same 
system of adaptations and relations, which they 
^lold to each other in the actual creation. The 
Pachydermata and Rodentia were kept in check 
the Carnivora — the Gallinaceous birds were 
controlled by the Accipitres. 
Le R^gne Animal, ^ ces 6poques reculees, 
ctait compose d’apres les memes lois ; il com- 
prenoit les monies classes, les memes families 
qoe de nos jours; et en elfet, parmi les divers 
systemes sur Porigine des 6tres organises, il n’en 
est pas de moins vraisemblable que celui qui en 
ait naitre successivement les differens genres 
pai des developpemens ou des metamorphoses 
graduelles.” (Cuvier, Oss. Foss. t. 3, p. 297.) 
This numerical preponderance of Pachyder- 
wiata, among the earliest fossil Mammalia, be- 
yond the proportion they bear among existing 
quadrupeds, is a remarkable fact, much insisted 
on by Cuvier ; because it supplies, from the 
colics of a former world, many intermediate 
orrns which do not occur in the present distri- 
ution of that important Order. As the living 
genera of Pachydermata are more widely sepa- 
