MAMMALS 303 



and certain others some of which yield valuable oil. It also 

 includes the vicious killer "whale," or orca, which "has the 

 appetite of a hog, the cruelty of a wolf, the courage of a bulldog, 

 and the most terrible jaws afloat." Although they are not 

 more than fifteen to twenty feet long three or four of them 

 will attack and destroy even the largest whale. 



The hoofed mammals, order Ungulata, include some of the 

 most familiar mammal forms. Most of the domestic animals, 

 as the horse, cow, hog, sheep and goat, belong to this order, as 

 well as the familiar deer, antelope, and buffalo of our own land, 

 and elephant, rhinoceros, hippopotamus, giraffe, camel, zebra, 

 etc., familiar in zoological gardens and menageries. The order 

 is a large one, its members being characterized by the presence 

 of from one to four hoofs, which are the enlarged and thick- 

 ened claws of the toes. The Ungulates are all herbivorous, 

 and have their molar teeth fitted for grinding, the canines being 

 absent or small. The order is divided into the Perissodactyla, 

 or odd-toed forms, like the horse, zebra, tapir, and rhinoceros, 

 the Artiodactyla, or even-toed forms, like the oxen, sheep, deer, 

 camels, pigs and hippopotami, and the Proboscidia, the ele- 

 phants. The Artiodactyls comprise two groups, the Ruminants 

 and Non-ruminants. All the native Ungulata of our Northern 

 States belong to the Ruminants, so-called because of their habit 

 of chewing a cud. A ruminant first presses its food into a ball, 

 swallows it into a particular one of the divisions of its four- 

 chambered stomach, and later regurgitates it into the mouth, 

 thoroughly masticates it, and swallows it again, but into 

 another stomach-chamber. From this it passes through the 

 other two chambers into the intestine. 



The deer family, Cervida, comprises the familiar Virginia, or 

 red, deer of the Eastern and Central States and the white- 

 tailed, black-tailed, and mule deers of the West, all belonging 

 to the genus Odocoileus, the great antlered elk or wapiti, 

 Cervus canadensis, the great moose, A Ice americana, largest of 

 the deer family, and the American reindeer or caribou, Rang- 

 ifer caribou. All species of the Cervidae have solid horns, more 

 or less branched, which are shed annually. Only the males 

 (except with the reindeer) have horns. The antelope, Antilo- 



