DRAGON FLIES INADEQUATE. 87 



its young, and whose generating powers are a thousand 

 fold greater; or, again, the omnivorous fly, whose sub- 

 sistence, in both of the active stages, drawn from the 

 sources of unceasing decay, is comparatively flung broad- 

 cast over the earth ? 



It is safe to say that, were the destruction of flies and 

 mosquitoes, through the agency of dragon flies, a vital 

 necessity to the preservation and continuation of the hu- 

 man race upon the earth, every dollar of wealth repre- 

 sented, whether by men, machines, or money, could be 

 expended in vain. 



Let us assume, for the sake of meeting every objection, 

 that dragon flies could be multiplied indefinitely by artifi- 

 cial means — 



1. At the time of their natural annual appearance. 



2. At all seasons. 



1. AS TO INDEFINITE MULTIPLICATION AT NATURAL 



SEASONS. 



As has been shown, dragon flies are incapable of domes- 

 tication. No matter how many may be introduced within 

 or in the neighborhood of a dwelling, their natural in- 

 stincts would prompt them to instantly betake themselves 

 to the vicinity of the nearest marsh or body of water, 

 while the flies and mosquitoes which most annoy us and 

 frequent our houses would be unmolested. (This fact 

 would absolutely dispose of the question of their utility 

 as destroyers of flies and mosquitoes in houses, in cities, or 

 in neighborhoods.) The vicissitudes of temperature would 

 soon terminate their existence, brief at the most, and the 

 relief afforded, at best, provided they were able to measur- 

 ably destroy other insects, would be but temporary. In 

 short, there is no creature which Is really so unable to 



