CONDITIONS INFLUENCING PREVALENCE 181 



advisers therefore selected Meeaii Meer, a barren plain, 

 almost uncultivated owing to the thinness of the soil. 



The extensive building operations necessary for the hous- 

 ing of the troops, however, soon honeycombed the level 

 surface with excavations of all sizes and the rising barracks 

 and bungalows soon afforded abundant shelter of the effective 

 sort dearest to the Indian Anopheles ; and hence, like all 

 new places, before long occupation has gradually ameliorated 

 the untidiness inseparable from new and growing places ; 

 the change proved no better than from " frying pan to fire." 

 Changing opinion led to the unhealthiness of the place being 

 ascribed to the absence of trees, and at great trouble and 

 expense, a separate shaft, filled in with soil, having to be 

 sunk through the limestone for each sapling, large numbers 

 of trees were planted, with no very perceptible result. The 

 cantonment still bears an evil reputation for malaria, but 

 half a century of occupation has wrought great improve- 

 ment in surface drainage and other kindred ameliorations, 

 and though still decidedly malarious, it is to day neither 

 markedly better nor worse than other stations in the 

 Province. In India, as elsewhere, especially during the 

 rains, many species of Mosquitoes certainly habitually 

 harbour in trees during the day, and there can be no doubt 

 that the proximity of trees, however pleasant to the eye, 

 is most undesirable if one wishes to keep a house free from 

 these pests. Colli (C. M., p. 141) states that An. bifurcatus, in 

 Italy, lives preferably in thickets, and that persons sleeping 

 in such places, even during the day, are frequently bitten ; 

 though the experience of Dr. Sambon and Low {B.M.J. 

 Dec. 8, 1900, p. 162) were contradictory in this respect. 



The explanation of this is probably that the observa- 

 tions were made in different months, for in India at any 

 rate our local species of Anopheles do not apparently find that 

 the shelter of trees is sufficient during the fierce heat of the 

 day, and prefer the deeper shade of buildings ; and, as far 

 as my somewhat limited experience extends, are not to be 

 found amongst trees during the day, though it is likely 

 enough that they may do so in parts of India where the 

 summer heat is less fierce than in the North West Provinces. 



