Lli'E-HlSTORY OF LEiTOMONAS MUSC.E DOMESTIC.E. 645 



On Some Stages in the Life-History of Lepto- 

 monas niviscse doniesticae, with some re- 

 marks on the Relationships of the Flagellate 

 Parasites of Insects. 



By 



J. S. Diiiikoi-iy. 



With Plate 31. 



In au endeavour to examine the Liflagellate character of 

 Herpetoinonas as described by Prowazek (20); I have dis- 

 sected and examined a nunsber of house-flies. At first 

 Musca doniestica was investigated^ as 1 had supposed that 

 this was the animal indicated by the word " Stubentliege." 

 In this country, however, M. doniestica does not seem to 

 be commonly infected, as I was unable to find the parasite iu 

 it, and Hewitt (6), who examined a good number of these flies, 

 was similarly unsuccessful. In the smaller house-fly, Homa- 

 lomyia canicularis, flagellate parasites were found to be 

 present, but Hewitt had confined himself to M. doniestica. 

 Still, the infections were very rare. I examined these flies 

 taken in three distinct localities : Chelsea and Wandsworth 

 in London, and Benfleet in Essex. Parasites were found in 

 Hies from each place, but always in a low percentage, about 

 4 per cent., of the flies examined. Other species of flies^^ have 

 been examined, but not in large numbers, so that it is not 

 surprising that no Herpetomouads have been met Avith in 

 them as yet. 



' I take tliis opportunity of expressing my thanlis to Mr. Aasteii, 

 ■\vlio liindly assisted nie in tlie identification of tliese flies. 



VOL. 56, PART 4. NEW SERIES. 45 



