346 H. M. WOODCOCK. 
described by Schaudinn, which in later development becomes 
the flagellar border of the membrane, i.e. the proximal part 
of the flagellum.} 
Turning to the question of the Trypanosomes, I have now 
succeeded in finding, in this series of slides, particularly in 
smears of the bone-marrow, a few very small Trypanosomes, 
forms which are no larger than the large individuals of 
Halteridium. When these little Trypanosomes (as in text- 
figs. 8 and 9) are compared with the large forms in the blood 
at this time (e.g. fig. 11), the difference in size is seen to be 
very marked. Between these extremes all intermediate 
TExT-FIG. 12. 
Small forms of Halteridium, from a liver-smear. The right- 
hand figure shows the appearance when two parasites are in 
one corpuscle, which is of frequent occurrence. K. Kineto- 
nucleus, or kinetonuclear element. ‘7. Trophonucleus, or 
trophonuclear element. x 2500. 
stages can be found. I could figure a series of regular grada- 
tions from the one to the other. Now, I have never seen 
the shghtest indications of division; even at this time, when 
the ‘Trypanosomes are less infrequent than at other times, 
e.g. early spring or late autumn. Hence, I consider that 
the larger forms have grown from smaller ones, and not that 
the small ones have arisen, by successive multiplication, from 
the large individuals. With regard to the origin of the very 
small Trypanosomes themselves, I am certainly disposed to 
think that they arise from adult Halteridia. This seems 
to me to be the most reasonable conclusion to arrive at, having 
regard to the data I have ascertained so far. 
1 T have now found this phase in two or three instances. 
