102 THE BEAUTIES OF NATURE chap. 



verbal description, however, can do justice to 

 the marvellous complexity of animal structure, 

 which the microscope alone, and even that but 

 faintly, can enable us to realise. 



LENGTH OF LIFE 



How little we yet know of the life-history 

 of Animals is illustrated by the vagueness of; 

 our information as to the age to which they 

 live. Professor Lankester ^ tells us that " the 

 paucity and uncertainty of observations on 

 this class of facts is extreme." The Rabbit is 

 said to reach 10 years, the Dog and Sheep 10 

 -12, the Pig 20, the Horse 30, the Camel 100, 

 the JElephant 200, the Greenland Whale 400 

 (?) : among Birds, the Parrot to attain 100 

 years, the Raven even more, The Atur Par- 

 rot mentioned by Humboldt, talked, but could 

 not be understood, because it spoke in the 

 language of an extinct Indian tribe. It is 

 supposed from their rate of growth that among 



1 Lankester, Comparative Longevity. See also Weismann, 

 Duration of Life. 



