INTEODUCTION. 5 



teenth century, under the name of Thur. The 

 species to which we owe the horse is extinct , the 

 type of the camel, the original dromedary, the type 

 of the dog* tribe are lost for ever. 



But they are replaced by numerous varieties of 

 animals so useful to us that they have been called 

 ' ' domestic animals," in producing which man has 

 attended to his own interests. 



These modified species of animals are increasing 

 in number daily. The term " domestic" animals 

 should extend over the whole, or, at least, the greater 

 portion of the animal world. Our readers are not ac- 

 customed to hear grubs, insects, animalculae, etc., 

 spoken of as " domestic animals." But do we not 

 rear our silkworms with as much care as our sheep or 

 our cows ? Do we not construct houses for our bees, 

 cochineals, snails, oysters, etc., as we do for our 

 rabbits, our chickens, or our horses ? Are not large 

 fortunes realized by the cultivation of a worm such 

 as the leech, or a grub such as the silkworm, as 

 readily as by the aid of the camel of the desert or 

 the Indian elephant ? Have we not seen a thimbleful 

 of some new insect or its eggs fetch as high a price 

 in the market as the choicest Cochin- China fowl ? 



It is too true that these inferior beings are com- 

 paratively new to_us in this light. But their study 

 affords far greater interest, and, in many cases, un- 

 doubtedly more profit, than that of superior animals. 



