BLOOD-SOCKING FLIES TRANSMITTERS OF DISEASE. 873 



September 1905 the Fieldman was kindly again placed at my disposal, 

 and on the very morning of his arrival discovered Stomoxys in the 

 Laboratory compound. Since then we have found Stomoxys calcitrans 

 common in Bombay during the damp months after the monsoon, 

 though it disappears at other seasons. 



Since then Mr. Lefroy has issued a Circular for the use of the Civil 

 Veterinary Department describing what ought to be done in regard to 

 the investigation of Biting Flies in India, and I cannot do better than 

 quote from it. 



" The Investigation of Biting Flies in India. 



" There are three main points in this inquiry which require to he 

 worked out from the entomological side before much progress can bo 

 made in determining how far insects transmit diseases in India : these 

 are (1) the identity of the flies that bite cattle, horses and man ; (2) the 

 life histories of these flies ; (3) their distribution in India. 



" (1) Biting-flies belong to several distinct groups ; excluding mos- 

 quitoes (Culicidce) and the smaller biting-flies ( Psycho didce, Chironomi- 

 dce, etc.), there are the Hippoboscidce (Horse-flies), Muscidce (Tsetse, 

 Stomoxys, &c), the Tabanidce (Gad-flies). 



" Of these, the Indian HippoboscidcE so far collected or sent in are 

 now being classified in Germany ; a named reference collection of these 

 will soon be available in India ; of the Muscidce, Stomoxys calcitrans 

 or a closely allied species is known, as well as a very peculiar form 

 only once found, which will be sent to the British Museum for classi- 

 fication as soon as possible. It is probable that others remain to be 

 found. The Tabanidce are a very large group, of which many have 

 been collected, and it is hoped these may be named at the British 

 Museum almost at once. The life histories of these insects are yet little 

 known, but any measures of checking them as well as an understanding 

 of their distribution must depend upon this knowled ge. The life history 

 of one Tabanid is knowD to conform to that of the group in general as 

 Isnown elsewhere, the life history of Stomoxys is known ; and there is 

 little doubt that the Hippoboscidce in India have the same absence of 

 larval stage as they have elsewhere. No more is known at present, 

 and it will be impossible to rear flies artificially for purposes of experi- 

 ment until more is known. 



" Of distribution, very little is known accurately; the Stomoxys of 

 Quetta is not known to be the same as that of Assam ; the Tabanidce 



