112 DRAGON FLIES VS. MOSQUITOES. 



It is absolutely certain that as a preliminaiy conclusion 

 I can confidently assert that the mosquito is injurious and 

 that its extermination or its abatement is a benefit. 



In discussing this problem we are compelled to avoid 

 any collision between the achievement of the desired end 

 by such means as we may employ and usages or comfort 

 of society. 



A remedy which considered in itself might be quite 

 efficacious is debarred from consideration if it interferes 

 with social usages or is a nuisance. In the discussion, 

 even, we should be inclined to reject any suggestion which 

 was recommended simply on the score of its being less 

 aggravating than the scourge. The remedy should be 

 complete in itself and harmless in its results, inoifensive, 

 and if possible attractive, so that with the eradication of 

 a pest we may substitute a pleasure or an ornament. 

 Further, we must select by preference all such remedies as 

 are the least exhausting, the least expensive, most readily 

 obtained, and most easily maintained. Furthermore, we 

 should inspect the various stages in the life history of the 

 mosquito and observe the requisite, feasible, or known de- 

 vices for its extermination at each stage. In this way it 

 might be possible to find a method which, applied at one 

 stage, was many times more effective, owing to the condi- 

 tions then prevalent, than a more difficult or costly one 

 used at a later or different period. 



There are obviously two distinct paths of experiment in 

 reaching practical results : first, by natural methods, and, 

 secondly, by artificial ; and as between ' these, other things 

 being equal and the results the same, the natural methods 

 are to be preferred if it can be shown that they will con- 

 tinue in action automatically after their introduction, or 



