^2 L. Rogers — Special "Report on Fever in Binajpur Disi* [Supplt« 



which very rarely enter houses, and have also not been yet found to be 

 naturally infected. This leaves us with only the A. Fuliginosus and 

 A. Listoni, the former of which has only once been found naturally in- 

 fected in the Punjab, while there it almost disappears before the fever 

 season begins. If it proves to have a similar seasonal distribution in 

 Bengal it may also be excluded from consideration as not being of any 

 material importance in the etiology of malaria. Some three years ago 

 a plan for destroying anopheles mosquitoes in Calcutta was initiated 

 tinder the idea that they only bred in small pools which could be easily 

 dealt with, as suggested by Major Ross. At that time I made a care- 

 ful search for the breeding-places of anopheles month by month for 

 more than a year in a selected area in a suburb of Calcutta, with the 

 result that I found them^ to be breeding in enormous numbers in 

 nearly all the tanks during the hot-weather months, that is, at the time 

 of the minimal malarial season. On the other hand, they were much 

 fewer in number during the rainy malarious time, but their distribution 

 was then different, the tanks being free from them, while the chief 

 breeding-places were small pools and more especially the shallow un- 

 even earth drains on each side of every road. Moreover, in these road- 

 side drains varieties of anopheles which can carry malaria were found, 

 whereas those which had swarmed in the tanks at an earlier period were 

 all A. Rossii, which we now know ^ are harmless as far as the spreading 

 of malaria is concerned. The measures which were being taken for 

 destroying the A. Rossii in the small pools and tanks, then, were only 

 money thrown away as far as malarial prophylaxis was concerned. 

 This example is mentioned to show that great circumspection is required 

 in recommending measures for destroying anopheles in Lower Bengal. 



A still more instr active example is that of the measures which have 

 been carried out under the directions of members of the Malaria Com- 

 mission during the last two years at great expense to test the practica- 

 bility of destroying anopheles in a portion of the very malarious canton- 

 ment of Mian Mir,* the results of which have recently appeared. In 

 this place the chief breeding-ground of the malaria-bearing variety 

 was the irrigation canals which traverse the cantonment. The results 

 of these operations will be familiar to the Sanitary authorities, but 

 briefly it may be said that the elaborate measures carried out persistent- 

 ly for two years resulted in only a slight diminution of the number 

 of anopheles in the houses of the treated area. On the other hand, 

 much good was obtained by prophylactic issue of quinine, and still more 



1 Reports of the Malaria Commission of the Royal Society. 

 8 Report on anti-malarial measures at Mian Mir. Scientific MemoirB, New 

 Series, No. 6, by S. P. James. 



