108 NATUKAl HISTOET. 



of when no longer needed ? "What is said of the Elk ? Of the Eein. 

 deer ? Of the Axis Deer ? How do the Moschidoe differ from the 

 Deer family ? What gives them their name ? How is the musk ob- 

 tained? What is said of the chemistry of this secretion ? Compare 

 the Antelopes with the Deer. What countries do they inhabit? Into 

 what sub-families are they divided ? What is said of the Springbok? 

 Of. the Gazelle ? Of the Oryx? Of the Kudu? Of the Gnu? What 

 are included in the family Camelidaj ? Where are the two species of 

 Camels found, and how do they differ? Show in what respects the 

 organization of the Camel is adapted to its habits and circumstances. 

 Describe its appearance. What is said of its docility? Of its mode 

 of rising from a kneeling posture ? Of its importance to man? What 

 is said of the Dromedary ? What of the Llamas ? What of the Gi- 

 raffe? 



CHAPTER XI. 



THE WHALE TRIBE. 



183. The water contains both the largest and smallest 

 of animals. In the sub-class now to be considered, the 

 Cetacea, or Whale tribe, we find the largest animals ex- 

 isting at the present time. Those monstrous terrestrial 

 quadrupeds, the Elephant and the Hippopotamus, are not 

 to be compared to the "Whale ; and even the smaller spe- 

 cies of this class, the Dolphin and Porpoise, are above 

 the average size of land animals. 



184. The animals of this tribe are, unlike all that we 

 have as yet considered, destitute of both hands and feet. 

 Though they are Mammals, they are fitted to live, like 

 the Fishes, in the water. They were classified among fish- 

 es by ancient zoologists, and are still spoken of as fish in 

 ordinary conversation. There is one group of Mammals 

 already noticed, the Seal family, which have some ap- 

 proach to the Whales both in form and habits (§ 101). 



185. The general shape of the Whales is like that of 

 fishes. The tail is, however, different in one respect. In 

 the Whale it is flat horizontally, not vertically, as in the 

 Fish. Li swimming, therefore, it moVes up and down, 



