ROSSES EXPERIMENTS WITH ANOPHELINES 43 



hundreds of yards to leeward of tl\e barracks). Suspicion 

 therefore first attaclied to the latter variety. 



" I determined, however, not to be swayed by such 

 considerations, but to make a most complete and 

 exhaustive test of all the varieties which I could 

 procure — even at the cost of repeating much of my 

 old negative work, during which, laborious as it was, 

 I may have o^'erlooked the object I was in search of. 

 A number of natives were employed to collect larvae 

 from far and wide round tlie barracks. These larva? 

 were kept in separate bottles, and when tlie adult 

 insects appeared they were released within mosquito 

 nets in which the patients were placed. The insects 

 were applied sometimes during the day in a darkened 

 room, and were sometimes fed at night. After 

 feeding, the gorged insects were collected in small 

 bottles containing a little water, and were kept for 

 several days before being dissected. The procedure 

 was therefore the same as before. But now, in order to 

 ensure at least definite negative results, redoubled care 

 was taken ; almost every cell was examined, even the 

 integument and legs were not neglected ; the evacua- 

 tions of the insects found in the bottles, and the 

 contents of the intestine, were scrupulously searched ; 

 at the end of the first examination staining reagents 

 were often run through the preparation and it was 

 searched again with care. The work, which was 

 continued from 8 a.m. to 3 or 4 p.m., with a short 

 interval for breakfast, was most exhausting, and so 

 blinding that I could scarcely see afterwards, and the 

 difficulty was increased by the fact that my microscope 

 was almost worn out, the screws being rusted with 

 sweat from my hands and forehead, and my only 

 remaining eye-piece being cracked, while swarms of 



