666 H. M. WOODCOCK. 



ovoid or rather oblong, which occupies the entire width of 

 the parasite at the point where it is situated. Its apparent 

 size is about IJ to 1^ // ]>y 1 ^. It is nearly always intensely 

 stained after Romanowsky stains, and shows no structural 

 details. 



The flagellum, at its proximal end, nearly always stops 

 short of the kinetonucleus ; only very exceptionally does it 

 appear to come into contact with the latter organella. In 

 this connection it may be emphasised that my specimens 

 are all from films properly fixed with osmic-acid vapour — 

 none from air-dried smears. Moreover, at the point where 

 the flagelluni terminates, a definite granule, staining rather 

 more deeply, can sometimes be made out quite clearly 

 (figs. 4, 28). Unfortunately in many cases the I'oot portion 

 C)f the flagelluni, which is probably intra-cytoplasmic, is not 

 well stained, and in these the granule cannot be made out. 



The cytoplasm stains pale blue, and is of fairly uniform 

 structure, appearing in some instances finel}' alveolar. 

 Occasionally a few stnall vacuoles or spaces are to be seen 

 in the cytoplasm, but I have not observed anything that 

 could be regarded as a definite, regularly occurring 

 organella of that kind. In some of these forms the cyto- 

 plasm is free from granules ; in others, however, granules 

 which stain bright red, and are of varying size, occur in 

 greater or less number (figs. 1, 3, and 27). These granules 

 are most probably of a chromatoid nature, derived from the 

 nucleus. 



The structure of the undulating membrane shows an 

 interesting feature. Running longitudinnlly in the broad 

 folds or pleats, usually about the middle, is a prominent 

 line, which stains blue — not red, like the flagellar border 

 (figs. 1, 2, 4, 28-32). With a good light it is not difficult 

 to make out that the part of the fold nearer to the body 

 appears slightly denser than that on the outer side of this 

 line, and stains faintly but distinctly blue, whereas the outer 

 part is practically colourless. The explanation of this 

 structure is that it represents a delicate intrusion of the 



