REPORT ON MOSQUITOES. 49 



builder, is found in the raijjroad engineer. I have in mind a 

 swamp area in Camden County, where a Y turn-out left a de- 

 pressed triangle of swampy area an acre or more in extent which 

 is now one of the most virulent breeders imaginable. An eight- 

 inch pipe put down when the dams were built would have 

 avoided all trouble at a slight expense. It will cost dollars now 

 to effect a cure, where cents would have served to prevent trouble. 

 Railroad ditches and drainage must be looked after then, and 

 in most cases a very simple bit of filling or clearing out will be all 

 that is necessary. I have always found railroad officials very 

 ready to co-operate in the work against mosquitoes, and believe 

 that any unsafe place on their land will be readily filled from the 

 nearest possible source as soon as their attention is properly 

 called to it. 



FOOD OF MOSQUITO LARV.^. 



The question, what good are mosquitoes anyway? — assuming 

 that everything is of some use — is usually answered by the state- 

 ment that mosquito larvje purify the water in which they live 

 by eating the micro-organisms that would otherwise render it 

 foul. In that way they would become of value as scavengers and 

 would be entitled to consideration; assuming that the premises 

 are correct. We would have to count out those species, however^ 

 that live only in clean water, and it would require proof that 

 some of the foul water in which wrigglers are found was really 

 improved to an appreciable extent. It would also have to be 

 demonstrated that the temperory and other pools in which mos- 

 quito larvae breed were really of some advantage; for to raise 

 mosquitoes to keep unnecessary and undesirable pools clean 

 would seem to be not quite in accord with modern ideas of the 

 fitness of things. Finally, it would also require proof that the 

 purification of such pools, assuming them to be desirable, could 

 not be obtained in some less irritating manner. 



It becomes a matter of interest, therefore, to know exactly con- 

 cerning the food of the wrigglers and to determine this, as well 

 as to seek a reason why certain species breed on the salt marshes 

 only, Mr. Horatio N. Parker, Health Officer of Montclair, New 

 Jersey, was invited to study the question from material to be sup- 

 plied by the office. 



Dr. L. O. Howard in his comprehensive little book on mos- 

 quitoes speaks specificall}^ of the food of Anopheles larvae only, 

 and what he says is worth quoting : "As already indicated, the 

 principal food of the larvae of Anopheles seems to be the spores 

 of algae; but, as we have pointed out, they will swallow anything 

 4 MO 



