120 GNATS OR MOSQUITOES — CHAPTER VII 



European town. On the other hand, unless my suspicion 

 that however close their resemblance, they are really 

 distinct forms be correct, the same larvae will be found 

 during the rains, alone or in company with Stegomyia 

 larva?, in almost drinkable water. Culex pipiens is of 

 course another typically domestic gnat, and C. annulatus, 

 spathipalpis, nemorosus, viridiventer and pidchnve7iter may 

 be cited as examples of field species, though the last is 

 perhaps, strictly speaking, a forest form. 



The habits of the different species of Anopheles larva? 

 also vary greatly An. Bossii is certainly essentially a domes- 

 tic species, and so too, I think, is A71. Sinensis with us, but 

 An. Jainesii, which appears to be the species that swarms 

 in the Madras paddy fields, is probably a field species, and 

 so too, it may be, is An. culicifacies, sp. n., which is 

 probably the species referred to by Mr. Aitken, in his 

 above-quoted note. 



During the past year I have observed the larvas of 

 An. Bossii in a variety of situations, but all essentially 

 " domestic." In the spring months, in upper India, none 

 are in evidence, and I first found them towards the end of 

 April, breeding in a pool beside one of the piers of the old 

 bridge across the Goomti, which flowed just beneath my 

 house in Lucknow. The pool was but a few yards long 

 by not more than six feet wide, and though it did contain 

 a certain amount of green filamentous vegetation, was 

 extremely foul. Still it is the nearest approach to the 

 ^'Anopheles pool" of the West African Malaria Com- 

 mission that I have met with inhabited by the larvae. 

 Typical pools of the sort I have indeed come across by the 

 dozen, but in no case have I met with them in such pools. 



The horizontal posture of the larvae was, however, very 

 noticeable, and when placed in a tray under lens, I could 

 also verify their peculiar trick of screwing round their heads 

 so as to look upward. During the dry, hot weather, how- 

 ever, their appearance is with us exceptional, though in the 

 damp eastern and southern parts of India they may be 

 found at any time of the year ; and it is not until the rains 

 ure fairly established that one can expect to find them in 

 any numbers. 



