Anopheles fly a long distance in search of food. 



and the third upwards of three quarters of a mile. On repeated 

 occasions the pools of the first group were found to contain larvae 

 within a week of a shower of rain, on three out of four occasions 

 the pools of the second group contained larvae, but on no occasion 

 were larvae found in the pools of the third group. These experi- 

 ments appeared to show that A. rossi, which was the species 

 concerned, would readily fly to a breeding place a quarter of a 

 mile away, that it would less readily fly to breeding places 750 

 yards away, and that it would never fly to breeding places three- 

 quarters of a mile away. It is obvious, however, that from none 

 of these experiments can any knowledge of the maximum flight of 

 "anopheles" be obtained ; they prove only that when these insects 

 are once established in a village they naturally select the nearer 

 breeding places in preference to those which are further away. 

 But in their search for food adult "anopheles " often become attracted 

 to villages which have no breeding places near at hand, and recent 

 observations have shown that they may be abundant in a place 

 even when there are no breeding grounds within a very long 

 distance. Captain James, I.M.S., in the operations at Mian Mir 

 already referred to, found on one occasion that numerous adult 

 4. ful'iginosus were present in the bazaars and houses when no 

 larvae of this species were to be found nearer than two and a quarter 

 miles, and Dr. Christophers, during the same operations, found 

 that the limit of flight of A. rossi had not been reached at three 

 quarters of a mile, and that although all breeding places of this 

 species had been obliterated up to this distance, it still appeared in 

 increasing numbers in the houses. The latter observer draws the 

 following conclusions from his experiments :- 



(1) In every case where an abundant food supply existed, 



anopheles travelled long distances (half a mile or 

 more) to reach it, and traversed an equal distance, if 

 necessary, to lay their eggs. Where, however, a suit- 

 able breeding place lay near at hand they did not 

 appear to pass it over. 



(2) The maximum distance of flight of A. rossi is not known 



with certainty, but under the conditions at Mian Mir 

 the experiments showed that they flew to and fro a 

 distance of more than half a mile. 



