2 
MAMMALIA. 
Boar, the prickles of Hedgehogs and the quills of Porcupines, and 
the wool of the domestic Sheep and of the equally domestic Alpaca. 
The colour of this same coat varies much less. The changes 
are nearly always from white to black, from reddish brown to 
yellowish. The brightest hues are found amongst the Monkeys 
and the Bats. 
As a general rule, the hair of the Mammalia falls off about 
spring or autumn, and is then replaced by new hair : this is what 
is called the shedding of the coat, which in some species takes place 
twice in the year. The scales, nails, horns, flakes of baleen (or 
so-called whale-bone), which certain Mammalia have, are pro- 
duced merely by the excessively close contact of the roots of 
the hair, the horny filaments of which join themselves firmly 
together, and compose solid laminae or blades. 
The general form of the body of Mammalia is determined by 
their bony skeleton. 
The form of the skull varies exceedingly among the Mammalia. 
Some, such as the Bhinoceros, have on the head or on the nose 
certain appendages. These appendages are sometimes merely the 
result of a very close conjunction of the roots of the hair, and 
belong to the skin ; such is the case with the horn or horns upon 
the face of the Bhinoceros. In other cases, the horns are placed 
on the skull itself, and belong to the frontal bones. All the 
animals provided with true horns are comprised in the natural 
order of Buminantia. 
When these appendages fall off every year, and are then re- 
newed, they are called bois {antlers), as in the case of the Stags. 
When they are hollow, investing a bony core, and are never 
renewed, they are called horns : these are found on the Ox, the 
Sheep, the Goat, &c.* 
Both horns and antlers vary a great deal in their shape. 
Other animals present a singular anomaly in the development 
of the nose. In the Elephant, we find this organ considerably 
elongated, and forming a trunk, which is used for prehension. At 
other times, this organ is less elongated, less retractile, as in the 
case of the Tapir and of many insectivorous animals, some of 
which are obliged to dig up the earth in search of their food. 
* A third kind of horn will be duly noticed in its place, that of the cabril or 
prong-horn (Antilocapra Americana ) . — Ed. 
Uu. 
