14 ECONOMIC MAMMALOGY 



almost immeasurable value to the human race of certain mammals that 

 provide us with meat, milk, butter, leather, furs and other products, 

 and those that in the past have furnished the chief means of transporta- 

 tion. On the other hand we shall see the great injury done by other mam- 

 mals by the destruction of crops, foodstuffs and other property, and 

 by interference in various ways with the industrial and commercial 

 operations of mankind. It is not practicable to exhaustively discuss any 

 of these phases of economic mammalogy in the several chapters devoted 

 to them, without making a ponderous and expensive volume of this 

 book, but much additional information bearing upon all these matters 

 may be found in Part n, where the economic relations of the various 

 groups of mammals are considered in systematic order. 



