No. 380.] FALSE PREMISES IN ECONOMIC ZOOLOGY. 579 
bad case for the kite. From another standpoint the evidence 
bears hard on the snake. As a variation to insect diet perhaps 
it has swallowed another snake. Is this an argument in its 
favor? Or it swallows a toad or frog, both of which live 
almost wholly on insect life. All this reminds us of Dean 
Swift’s rhyme : 
So, naturalists observe, a flea 
Has smaller fleas that on him pre 
And these have smaller still to bite ’em ; 
And so proceed, ad infinitum. 
So the plot thickens until we are tempted to despair of the 
utility of these investigations. A weed is a useful plant mis- 
placed; so also is the hawk, the mouse, the snake, or the insect 
a noxious animal when we unwisely alter the conditions of its 
struggle for existence. In nature’s order all have their place 
in the economy of creation. 
Two notable groups of injurious mammals in this country 
are the jack rabbits and the spermophiles, or ground squirrels, 
of the West. Their combined ravages amount to agricultural 
losses of tens of thousands of dollars annually and cover a 
vast extent of country. This condition of affairs has become 
a national question in the last decade, and was a state question 
long before that. The vast increase of these rodents is directly 
due to man’s destruction of rapacious mammals, birds, and 
reptiles, especially of the coyote, or prairie wolf, in these 
regions ; also to the increased amount and improved quality of 
food supply attending the settlement of the country. This is 
a matter in which no restoration of primitive conditions is 
either feasible or desirable, except so far as rapacious animals, 
wrongly considered harmful, can be encouraged to increase. 
The effectual devices recommended in the Bulletins of the 
Department of Agriculture, and adopted by our western 
brethren for the destruction of jack rabbits and spermophiles, 
as well as the noxious pocket rat, or gopher, are strong proof 
of the practical value of economic study along these lines. 
l Bulletin No. 4,“ The Prairie Ground Squirrels of the Mississippi Valley,” 
1893. Bulletin No. 5,“ The Pocket Gophers of the United States,” 1895. Bul- 
letin No. 8,“ The Jack Rabbits of the United States,” 1896. 
