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Herpetomonas pediculi, nov. spec, Parasitic in the Alimentary 

 Tract of Pediculus vestimenti, the Human Body Louse. 

 By H. B. Fantham, D.Sc, B.A., Christ's College, Cambridge, and Liverpool 

 School of Tropical Medicine. 



(Communicated by Prof. Sir Eonald Eoss, K.C.B., F.B.S. Eeceived 

 November 24, 1911,— Eead January 18, 1912.) 



[Plate 14.] 



Introduction. 



The organism which forms the subject of this paper is a small flagellate 

 Protozoon occurring in the alimentary tract of the body louse, Pediculus 

 vestimenti (P. corporis). The flagellate belongs to the genus Herpetomonas, 

 and is, I believe, now recorded for the first time. I propose for it the name 

 Herpetomonas pediculi, using the name Herpetomonas in the sense of 

 Saville-Kent (1881), the founder of the genus. 



The parasite was first seen by me nearly three years ago, when working in 

 Cambridge. At that time, material being scanty and apparently difficult to 

 obtain, there seemed to be no special reason for recording the presence of yet 

 another species of Herpetomonas, though the possibility of lice acting as 

 carriers of disease was realised. Other researches were then in progress, but 

 I have given H. pediculi intermittent attention ever since I discovered it. 

 Lately it has been suggested that flagellates belonging to the genera 

 Herpetomonas and Crithidia occurring in the digestive tracts of blood- 

 sucking insects are really stages in the life-history of vertebrate trypano- 

 somes. In consequence of the importance of the subject in relation to the 

 transmission of trypanosomes and of the increasing attention devoted to 

 leishmaniasis (or human herpetomoniasis), I have resumed my study of 

 Herpetomonas pediculi, and have found its complete life-cycle. 



I hope to show that, although Herpetomonas pedicidi might easily be 

 confused with dangerous parasites transferable to man by the bite of the 

 insect hosts, yet it is really a harmless flagellate of the gut of the louse. 

 Bred lice, fed on my own blood, have been used in the research. 



Material and Methods. 

 The hosts of Herpetomonas pediculi were common body lice, Pediculus 

 vestimenti. The lice were originally obtained from the bodies of infested 

 children and from verminous clothing recently removed from the body. 



