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become very finely granular, very few large granules remaining. The 
nucleus in turn gradually constricts in two, the line of separation 
coinciding with that of the long axis of the body of the organism 
(Figs. 2, 3, 4). Separation ultimately occurs, the ends nearer the 
blepharoplasts first becoming free. 
Division is sometimes repeated before the daughter organisms 
separate, and a rosette of parasites is thus formed (PI. V, Fig. 18). 
The members of a rosette do not acquire their flagella simultaneously, 
and they separate when the flagella are formed ; consequently groups 
containing both flagellated and non-flagellated forms are found (Fig. 18). 
The division of the flagellated forms usually commences with that 
of the flagellum, though the blepharoplast in such cases constricts 
at the same time (PI. V, Figs. 37, 38). Further division of the 
flagellum may be arrested considerably. Longitudinal fission proceeds 
as in the pre-flagellate forms. The blepharoplast and nucleus divide 
(Figs. 39, 40), and the daughter nuclei so formed migrate to opposite 
sides of the organism. The flagellum then divides (Fig. 39) and 
separation of the bodies commences (Figs. 40, 41, 42). The separation 
is aided by the vigorous movements of the flagella, which cause a 
very rapid divergence of the daughter Herpetomonads (Fig. 43) until 
they are in a straight line with one another (Fig. 44) when final 
separation occurs. Repeated longitudinal division results in the pro¬ 
duction of very narrow, slender forms (Fig. 35). 
Post-flagellate division is really of the nature of a preparation for 
encystment. When about to divide the parasite shortens and thickens. 
Division of the ordinary flagellate type then occui’s (PI. V, Fig. 51). 
As division proceeds (Fig. 52) the body shortens, the protoplasm con¬ 
centrates around the nucleus, and the flagellum appears either to be 
partly absorbed or to degenerate (Figs. 52, 53), for it gradually disappears 
(Figs. 53, 54). A second division then occurs (Figs. 54, 55); the tiny 
oval daughter forms (Fig. 56) show no flagellum, and gradually, as a 
gelatinous cyst is secreted around them, form small cysts (Figs. 57—68). 
Sometimes the two daughter forms and the cysts they produce 
remain side by side (PI. V, Fig. 62). At other times they separate 
and become isolated. Groups of cysts (Fig. 68) are not uncommon in 
the rectum. During the division prior to encystment, the flagellates 
may fix themselves to the walls of the rectum, and consequently the 
cysts are attached to some extent to the gut wall, but not so firmly as 
to prevent them being detached and passing out with the faeces of 
the host. 
