516 Herpetomonas pediculi, n. sp., Parasitic in P. vestirnenti. 



trypanosome, for I have fed the infected lice from the time of hatching to the 

 time of death on my own body, and have made detailed examinations of my 

 own blood by smears, thick films, and by cultures, as well as by sub- 

 inoculations into white rats, none of which has ever given indication of 

 trypanosomes during three years of experiments. Animals inoculated with 

 IT. pediculi from the gut of lice have also shown no parasites. 



8. H. pediculi is a parasite of the louse, Pediculus vestirnenti, and shows no 

 connection with any vertebrate trypanoeome. Also, it is not connected with 

 Leishmania. 



REFERENCES. 

 Further references will be found in some of the memoirs cited. 



Leger, L. (1902). " Sur la structure et le mode de multiplication des Flagelles du genre 

 Herpetomonas, Kent," 1 C. R. Acad. Sci., Paris,' vol. 134, pp. 781 — 784. 7 figs. 



Neumann, L. G. (1911). "Notes sur les Pediculides, II," 'Archives de Parasitologic,' 

 vol. 14, pp. 401—414 (Pediculus, pp. 410—413). 



Porter, Annie (1909). " The Life-cycle of fferpetomonos jm-uf mn (Leger), Parasitic in the 

 Alimentary Tract of Nepa cinerea," ' Parasitology,' vol. 2, pp. 367 — 391. 1 plate. 



Porter, Annie (1911). "The Structure and Life-history of Crithidia pulicis, n. sp., 

 Parasitic in the Alimentary Tract of the Human Flea, Pule.r irritans," 'Parasi- 

 tology,' vol. 4, pp. 237 — 254. 1 plate. 



Saville-Keut, W. (1881). ' A Manual of the Infusoria.' 3 vols. London. (Herpetomonas, 

 p. 245.) 



Warburton, C. (1909). " A Preliminary Investigation on Flock as a Possible Distributor 

 of Vermin, and on the Life-history of the Body Louse (Pediculus vestirnenti)," 

 ' Reports to Local Government Board on Public Health and Medical Matters ' (New 

 Series, No. 2). 5 pp. London, H.M. Stationery Office. 



EXPLANATION OF PLATE 14. 



All figures outlined with Abbe-Zeiss camera lucida, after wet fixation with osmic 

 vapour and absolute alcohol and staining with Giemsa's solution ; 2 mm. apochromatic 

 objective (Zeiss) and compensating oculars 8 and 12 used. Magnification 1500 diameters. 



Figs. 1 — 7 represent pre-flagellate and intermediate forms of H. pediculi from the 

 digestive tract of the larva or the fore-gut (cesophagus and proventriculus or anterior 

 lobe of the stomach) of the adult Pediculus vestirnenti. 



In fig. 1 note the chromatophile or pink -staining finely granular area from which 

 the flagellum arises. 



In figs. 2, 3, 4, 6, 7 note the gradual lengthening of the flagellum and elongation 

 of the body. 



Fig. 5 represents a late pre-flagellate organism dividing. 

 Figs. 8 — 18 show flagellate parasites from the stomach and anterior part of the intestine 

 (or mid-gut) of the adult louse. 

 Fig. 8. Young flagellate. 



Fig. 10. Flagellate showing body twisted or folded over about the middle of its 

 length. 



