582 ZOOLOGY. 
Insectivora, and bats should be associated with the Edentates 
in Bonaparte’s division (or, as Gill terms it, super-order) 
of Ineducabilia (which corresponds to Owen’s sub-class 
Lissencephala). In these four orders, then, the cerebrum is 
small, smooth, with none or few convolutions; in front 
it does not cover the olfactory lobes, and behind leaves 
the cerebellum wholly or partly uncovered. 
On the other hand, in the super-order Hducadilia, com- 
prising the following order: Cete, Sirenia, Proboscidia, Hy- 
racotdea, Toxodontia, Ungulata, Carnivora, and Primates, 
the brain has a relatively large cerebrum, behind overlap- 
ping much, or all, of the cerebellum, and in front much, or 
all, of the olfactory lobes (Gill). The cerebrum is also con- 
voluted ; the convolutions increasing in number and com- 
plexity, until we reach the apes and man, and accompanied. 
by increasing intelligence and capability for mental im- 
provement. Other important characters are mentioned by 
Owen and by Gill in support of this arrangement. 
In the smooth small cerebrum, as well as in other re- 
spects, the Zneducadilia are related, together with the mar- 
supials and duckbill, to the birds and reptiles. In‘ the 
cloaca, the convoluted trachea, the long, slender, beak-like, 
toothless jaws and the gizzard of the ant-eaters, the quills 
of the porcupine and hedge-hog, the proventriculus or crop 
of the dormouse and beaver, in the growing together of the 
three chief metatarsals of the jerboa, asin birds, in the keeled 
sternum and wings of the bats, there are points of resem- 
blances to birds. Owen, whom we have quoted, also adds 
the aptitude of the bats, insectivores and certain rodents 
‘‘to fall, like reptiles, into a state of torpidity, associated 
with a corresponding faculty of the heart to circulate car- 
bonized or black blood.’’ 
However, there are points in which these orders are re- 
lated to the lemurs and monkeys. 
Order 2. Glires. (Rodentia.)—The rats, squirrels, por- 
cupine, and beaver are common examples of this extensive 
group. They differ from other orders in the large incisors, 
the dental formula of which is normally } ($ in Leporide 
and Lagomyide@), and in the absence of canine teeth. The 
