122 DRAGON FLIES VS. MOSQUITOES. 



oil of peppermint, and oil of pennyroyal. A very strong 

 infusion of roots of Triticum repens is successfully used 

 at Simbirsk as a preventive against the attacks of mos- 

 quitoes, etc. (Ross. Ent. Soc, X., page 10. A weak 

 solution of quassia wood boiled in water has also been 

 recommended against bites of mosquitoes. (Nat., XXII., 

 page 11, 1880.) 



CoNCLUDixG Recommendations. 



The results of this examination of the problem laid 

 before the scientific world by Dr. Lamborn, and recom- 

 mendations flowing from these results, are : — 



1. A closer study of the life history of the dragon fly, 

 which invokes for its objects the exact determination of 

 the period of the larval condition, habits, etc. 



2. I recommend the employment of the lamps men- 

 tioned (see Plates VIII. and IX,) in swamps and along 

 coast marshes, in damp woods, and about houses and hotels. 



3. The raising of fish in ponds and the encouragement 

 of raising water fowl in regions where fresh water is 

 abundant. 



4. Where the conditions are favorable and their use 

 will not lead to the interference with health, I believe the 

 use of coal oil in the waters of the estuaries of our rivers 

 and on the rain invaded areas of deep woods will be ef- 

 fective in destroying the mosquito in its larval stages. 

 Astringents, as logwood or alum, will also prevent the 

 growth of the mosquito in its incipient stages. 



5. Drainage of swamps. This is of immense value 

 and probably a complete remedy where it can be inexpen- 

 sively used. 



