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and isolated pools near the foreshore filled in ; in experiments made 

 by the author the ponds selected were comparatively clear of surface 

 weeds, and mosquito larvae were found near the margin ; these 

 ponds were stocked with larvae- eating fish and after a few days were 

 examined, with the result that no larvae could be found excepting 

 above some patches of surface weed ; this weed was removed, and 

 a further search made the following day, gave negative results. 



The depressions formed when constructing irrigation tanks, railways, 

 etc., in India afford extensive breeding-grounds for mosquitos ; these 

 should be filled in, if it is impossible to drain them ; or if they are 

 extensive and hold water for a long time, they should be linked up by 

 means of trenches and stocked with fish. Shallow swamps and isolated 

 pools should be drained, or if this is not possible, owing to the nature 

 of the country, it is best to construct a pond at the lowest level and 

 drain the swamp by open trenches into it. In malaria-infected areas 

 when water is conveyed by small open irrigation channels, their course 

 should be clearly defined, and all obstructions removed ; the sides 

 being protected by stone slabs. In the town of Cuddapah 50 per cent, 

 of the wells were found infested with the larvae of A. stephensi; but 

 the worst of these were found free from larvae three days after the 

 introduction of suitable fish {Haplocliilus). The destruction of small 

 fish by basket traps of minute mesh should be prohibited in paddy 

 fields, which form very good feeding grounds for the small Haplochihis . 

 Holes dug for the purpose of obtaining w^ater for young Casuarina 

 trees form most dangerous mosquito breeding places, and these are to 

 be found in every plantation along the coast ; in the interests of public 

 health the Government should compel owners of plantations to fill in 

 such pits, and also the trenches often dug in coconut plantations. 

 In street drains where it is impossible to get rid of all the water, kerosene 

 oil should be used freely at least once a week. Drainage channels 

 on the sea-coast subject to tidal influence are generally free from 

 larvae and well stocked with fish, except where they are obstructed. 



In Southern India A. culicifacies is most ubiquitous in its selection 

 of a site for ovi position, but generally prefers clear water ; A. 

 barbirostris occurs in tanks, shady pools, pot-holes in rocks, stagnant 

 waters, etc. ; A.fuliginosus in marshes, swamps, paddy fields, etc. ; A. 

 stephensi in wells, puddles, cisterns, etc. ; and A. ivillmori in hill 

 streams and marshes. 



Among the natural enemies of mosquito larvae are small 

 Crustaceans, such as species of Daphne ; Dytiscid beetles, either as 

 larvae or adults ; Notonecta glauca ; and the following fish : — All 

 species of Chela, especially the smaller ones, all species of Rasbora, 

 small species of Barilius, all species of Haplochilus, small species of 

 Barbus (all these being suitable for tanks, big ponds and swamps). 

 For paddy fields, wells and small ponds all species of Chela, Haplochilus, 

 and Polyacanthus and Therapon jarbua are recommended. 



Cruickshank (J. A.) & Wright (R. E.). Filariasis in Cochin.— 

 Indian Jl. Med. Res., Calcutta, i, no. 4, April 1914, pp. 741-785, 

 1 map, 7 pi. 



The work described in this paper was carried out during ten visits 

 paid by the authors to Cochin between July 1912 and June 1913, the 



