2 MAMMALIA, 



Boar, the prickles of Hedgeliogs 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 rejjlaced 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 Rhinoceros, have on the head or on the nose 

 •lertain 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 Rhinoceros. In other cases, the horns are placed 

 on the skull itself, and belong to the frontal bones. AU the 

 animals jirovided with true horns are comprised in the natural 

 order of Ruminantia. 



When these appendages fall off every year, and are then re- 

 newed, they are called hois (antlers), as in the case of the Stags. 

 When they are hollow, investing a bonj^ core, and are never 

 renewed, they are called horns : these are found on the Ox, the 

 Sheep, the Goat, &c.* 



Both horns and antlers varj^ a great deal in their shape. 



Other animals present a singular anomalj' 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 torn will he duly noticed in its place, that of the oabril or 

 prong-horn [Antilocapra Ameyicana) . — En. 



