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it is crowded with irregular dark-staining red and purple granules. 
( b ) Slender forms (10'8/a x 2/a), with a Herpetomonas-\\ke facies, ap¬ 
pear here and there (Plate III, Fig. 18). The posterior portion of the 
body is tapering; the undulating membrane is very narrow, and has a 
long free flagellar portion (9/a). The nucleus is small, and is situated 
half-way along the body. In one case a minute, deeply-staining granule 
could be seen lying between the nucleus and the slightly anterior 
blepharoplast—otherwise the cytoplasm was singularly free from dark- 
staining granules, (c) Still another type may occasionally be seen 
(Plate III, Fig. 19 a, b ), of very small size (4/a long), with an oval to 
cigar-shaped body, a long free flagellum, no undulating membrane 
discernible, and a relatively large posterior blepharoplast, generally 
situated behind a vacuole. Of nucleus there is no trace, unless the 
granules distributed in the cytoplasm be regarded as a nucleus in a 
diffuse condition. 
Only one clearly marked instance of division was met with (Plate 
III, Fig. 17). The daughter forms were still attached by the distal 
portion of the undulating membrane, which is apparently the last organ 
to divide. 
(3) Post-flagellates. Most of the parasites are in this condition. 
Their dimensions vary from 2'5/a x 2'5/a to 7/a x 6/a, and all stages of the 
gradual rounding-up and encystment can be seen (Plate III, Figs. 21 to 
26). A rosette of oblong dividing forms is shown in Fig. 20. The para¬ 
sites are attached centrally by their reduced flagella, the blepharoplasts 
have in two cases divided, and the characteristic strings of chromatin¬ 
like granules in the cytoplasm are well seen. The distal portion of the 
flagellum becomes gradually reduced to a sort of pink-staining “ brush ” 
which is gradually absorbed. The intracellular portion is distinguish¬ 
able for some time, and it appears to take its origin in a pinkish, 
vacuole-like area in front of the nucleus. Its connection with the 
blepharoplast becomes lost, and that body may wander to the posterior 
end of the cell, or become indistinguishable from other granules in the 
cytoplasm (Figs. 22, 23 and 26). The nucleus generally stains rose-red 
without distinct reticulum, the chromatin being massed peripherally. 
In Fig. 21 the nucleus is apparently the first part of the cell to divide, 
and is shown in process of constriction : in Fig. 27 the two halves are 
redividing before the bulk of the cell has completed the first division. 
Frequently the nucleus shows signs of disappearing altogether: in 
Fig. 22 it has fragmented into three parts, and in Figs. 24 and 25, it is 
reduced to a mass of diffuse chromidia. The most advanced stage of 
