73 ON THE SENSES OF ANIMALS. 



instances have been known in which he has pined 

 and died when separated from his master. The 

 horse, too, obeys cheerfully the voice of his driver; 

 the huge elephant pays willing obedience to his 

 keeper ; and the patient camel bends to the earth 

 to receive his load. 



There can be no doubt but that the possession 

 of a very nice sense of taste and smell is the cause 

 which enables animals to select their food. The 

 larger horned cattle, such as cows, will eat only 

 about two hundred and seventy kinds of plants out 

 of the fifty thousand which the vegetable kingdom 

 contains. They leave all the rest untouched, 

 however beautiful and nutritious they may be. 

 The horse feeds upon two hundred and sixty-two 

 species; whilst the hog, still more choice in its 

 selection in a wild state, eats only of seventy-two, 

 and will not taste any other. Caterpillars show 

 the same capacity of selection; for if thirty differ- 

 ent kinds of leaves are put in their way, they will, 

 perhaps, touch only one out of the whole number. 

 The silk-worm subsists on the leaves of the mul- 

 berry tree, and the persons engaged in the rearing 

 of silk-worms are under the necessity of cultivat- 

 ing this tree on purpose to support them. 



Thus, looking at a pasture-field, it will be seen 

 that some places are cropped quite bare, and others 

 left untouched ; but as the tastes of animals vary, 

 those plants which are refused by one species are 

 eaten by another. Some plants, too, which are 

 poisonous to one creature, are eaten greedily, and 



