STUDY OF ENTOMOLOGY 53 



gain to health for tlie inmates is worth the outlay. 

 Under any circumstances it is now recognised in 

 every civilised community that a mosquito net to 

 sleep under is as essential as tlie bath in the morning. 

 Time was when it was supposed to be effeminate to 

 use a net, and what countless lives and shattered con- 

 stitutions have resulted in consequence ! 'J'he net now is 

 as essential to a man or woman as any article of attire. 



3. With regard to the measures to exterminate 

 the anophelines, a very large subject is opened up. It 

 is in the first place the measure which strikes at the 

 root of prevention, and it is the procedure, as first 

 pointed out by Ross, that we must all aim at. Get 

 rid of the breeding places of the enemy. And the 

 very first thing to do is to locate them. Here the 

 entomologist is necessary to point out where they are, 

 and it surely is a sign of the progress of tropical 

 sanitation that the services of entomologists are being 

 made use of far more frequently than formerly. The 

 closer study of the life history of the mosquito has 

 indicated to us that man has most powerful allies to 

 help him carry on his war in the form of the natural 

 enemies of mosquitos. All living things have their 

 natural enemies, and mosquitos are no exception. They 

 have their enemies whilst on the wing, such as dragon- 

 flies and birds, but tliey are most vulnerable in the 

 larval stage whilst in water. Here tliey form the 

 natural food of fish and of certain water insects. It 

 is now, therefore, the rule to stock ornamental ponds, 

 lily-tubs, canals, trenches, etc., with fish — larger fish 

 like the gold fish for the larger collections of water, 



