A PARASITE OF LICE 



57 



living. Mature flagellates sometimes become en- 

 tangled together, and so form rosettes (Fig. 13, C). 



Longitudinal division progresses rapidly (Fig. 14, 

 A-D), and when this has proceeded for several 

 generations, the organisms need a rest, and also a 

 change of host. Each proceeds to concentrate its 



FIG. 14 HERPETOMONAS PEDICULI : DIVISION FORMS 



A, Full-grown flagellate, blepharoplast dumb-bell shaped ; B, com- 

 mencement of division, blepharoplast constricted, flagellum 

 divided into two ; C, later stage of division, nucleus divided 

 into two ; D, commencement of separation of the daughter 

 organisms 



body substance little by little (Fig. 15, A -E), to with- 

 draw its flagellum, and finally to form its thin but 

 very resistant cell-wall; in fact, to reach the con- 

 dition of the post-flagellate (Fig. 15, F). Voided 

 with the dejecta of its host, it remains passive and 

 uninjured until some new host absorbs it, when its 

 activities recommence. 



