Vlll INTRODUCTION. 
The first class, or Mammalia, consists of such animals as produce 
living offspring, and nourish their young ones with milk supplied 
from their own bodies ; and it comprises both the quadrupeds and 
the cetaeea. 
This class was divided by Linnasus into seven Orders : viz. 
primates, bruta, ferae, glires, pecora, lellnx, and cete, or whales 
The characteristics of these were founded, for the most part, on the 
number and arrangement of the teeth ; and on the form and con- 
struction of the feet, or of those parts in the seals, manati, and 
the Cetaeea, which supply the place of feet. 
ORDERS OF MAMMALIA. 
I. PRIMATES. Having the upper front teeth generally four in 
number, wedge-shaped, and parallel ; and two teats situated 
on the breast, as the apes and monkeys. 
II. BRUTA. Having no front teeth in either jaw; and the feet 
armed with strong hoof-like nails, as the elephant. 
III. FERJE. Having in general six front teeth in each jaw ; a 
single canine tooth on each side in both jaws ; and the 
grinders with conic projections, as the dogs and cats. 
IV. GLIRES. Having in each jaw two long projecting front teeth, 
which stand close together ; and no canine teeth in either 
jaw, as the rats and mice. 
V. PECORA. Having no front teeth in the upper jaw ; six or eight 
in the lower jaw, situated at a considerable distance from the 
grinders ; and the feet with hoofs, as cattle and sheep. 
VI. BELLU^E. Having blunt wedge-shaped front teeth in both 
jaws ; and the feet with hoofs, as horses. 
VII. CETE. Having spiracles, or breathing-holes on the head ; fins 
instead of fore-feet ; and a tail flattened horizontally, instead 
of hind feet. This order consists of the narvals, whales, 
cachalots, and dolphins. 
The second class, or Birds, comprises all such animals, as have 
their bodies clad with feathers. Their jaws are elongated, and 
covered externally with a horny substance called a bill or beak, 
which is divided into two parts called mandibles. Their eyes are 
furnished with a thin, whitish, and somewhat transparent membrane, 
that can at pleasure be drawn over the whole external surface like 
a curtain. Birds respire by air vessels, which are extended through 
their body, and which, in the abdominal cavity, adhere to the 
