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MURIEL ROBERTSON. 
runs forward from the blepharoplast, ending, as usual, in a 
free whip. It stains green with Twort’s combination and 
faintly with Delafield — more deeply with iron hsematoxylin. 
The undulating membrane is developed to a varying degree, 
but is never much frilled. 
Two other structures remain to be described. The first is 
a small granule only staining in Heidenhaiu preparations. It 
lies posterior to the kinetonucleus and often near the pos- 
terior end of the body. Sometimes it appeal’s to be connected 
to it by a delicate strand. This granule is also found in the 
Giemsa preparations and is clearest in the Trypanosome 
phase. It has possibly something to do with the anchoring 
of the kinetonucleus (figs. 9 and 10). 
The second is an element which I have never seen in the 
dried preparations at all, but which is a pretty constant feature 
in the wet films and appears equally so with all the four 
stains used. Just anterior to the trophonucleus a small con- 
densation is to be observed in the protoplasm surrounded by 
quite a definite little halo. In rather dark Heidenhaiu pre- 
parations it stains almost black (figs. 9 and 10), with Delafield 
it looks grey-blue with soft outlines, and is usually only very 
slightly darker than the surrounding protoplasm (figs. 8, 11 
and 19). It stands out clearly in these films more by reason 
of the halo than on account of its greater depth of colour. 
In Fuchsine films it is very clear : it is also visible in Twort’s 
preparations but does not take on the red colour. It some- 
times appears to be double. The nature and function of this 
structure is quite obscure ; it is most clearly visible in the 
Trypanosome stage and its position is quite constant, but it is 
also present in the earlier phases. The position of the kineto- 
nucleus often obscures it in these and makes it difficult to 
see. 
'I’lie Trypanosome just described arises, as has been said, 
from a rounded resting form which develops a flagellum (figs. 
1 — 11). The body gradually elongates and the kinetonucleus 
migrates backwards until it is well posterior to the ti’opho- 
nucleus. An undulating membrane develops during this pro- 
