MAN. 9 



posed of two hemispheres ; and a muscular diaphragm 

 separates the cavity of the chest from that of the abdo- 

 men. Mammals breathe air by means of lungs, have 

 warm blood, a circulatory system consisting of a heart 

 with four cavities, arteries which carry the blood from 

 the heart to all parts of the body, veins which conduct 

 the blood back to the heart, and capillary vessels which 

 connect the termination of the arteries with the begin- 

 ning of the veins. The nose forms part of the face, the 

 eyes are protected by two lids, and the ears are com- 

 posed of three parts, and nearly all mammals are en- 

 dowed with vocal organs. The Mammals are the high- 

 est in rank of all the animals of the globe. The number 

 of species is about two thousand, distributed among the 

 following orders: Bimana, Quadrumana, Carnivora, Her- 

 bivora, Mutilata, Chiroptera, Insectivora, Rodentia, Eden- 

 tata, Marsupialia, and Monotremata.* 



SUB-SECTION I. 



THE ORDER OF BIMANA, OR MAN.f 



THE structure of Man is essentially the same in kind 

 as that of other mammals, differing only or mainly in de- 

 gree ; yet the degrees of difference separate him widely 

 from all other animals, and place him in an order by 

 himself, and far above all other organized beings. He is 

 the only animal to which the erect position is natural ; 



* These orders are described in the following pages in the order in which 

 they are here given ; but the relation of these groups to one another is bet- 

 ter shown if we write their names thus : * 



I. Sub-Class of Viviparous Mammals or Placental Mammals* 



Bimana, 



Quadrumana, Chiroptera, (analogues of the Quadrumana) 



Carnivora, Insectivora, ( " " " Carnivora) 



Herbivora, Rodentia, ( " " " Herbivora) 



Mutilata, Edentata, ( '' " " Mutilata). 



II. Sub-Class of Semi-viviparous Mammals or Ooticoids. 

 Marsupialia, 

 Monotremata. 



t Some naturalists put both Man and Monkeys in one order, and call 

 the order Primates. 



