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are not easy to trace owing to the difficulty of distinguishing it till it is 
of some thickness. Its connection with the kinetonucleus is the same 
as that of the first rhizoplast. In some of the dried specimens the new 
rhizoplast is seen growing out from a point on the surface of the pale 
half of the kinetonucleus as pointed out above (PI. XII, figs. 31 and 34). 
The further division of the kinetonucleus is very clearly seen in the 
specimens fixed without drying. The elongated kinetonucleus becomes 
constricted towards the middle, and the two halves separate more and 
more, though they remain connected by a fine filament even up to the 
stage when the protoplasm of the parasite is commencing to divide 
(PI. XIII, figs. 7, 8, 10, 14). Meanwhile, the new rhizoplast has been 
gaining in thickness and increasing in length till it commences to grow 
out from the surface in the form of a new flagellum. This new 
flagellum is at first thinner than the already existing one. At first 
the free extremity is closely applied to the original flagellum (PI. XIII, 
fig. 4). I believe this appearance is due to the fact that the flagellum 
is enclosed in a delicate protoplasmic sheath, a continuation of the 
superficial ectoplasmic layer of the body. The new flagellum grows 
outwards within the sheath of the first flagellum and it is only when 
the new flagellum is fairly long that this sheath divides longitudinally 
so that each flagellum has its own sheath and can exercise independent 
movements. The new flagellum increases in length and thickness till 
when the division of the flagellate is complete it may not be equal in 
length to the original flagellum. I think that in the majority of 
trypanosomes the formation of a new flagellum takes place in a similar 
manner and the distal end of the new flagellum is within the sheath of 
the original flagellum, and often closely held to it so that the end may 
appear to unite. Such an appearance often gives one the impression 
that the new flagellum is forming by longitudinal division of the old 
one, but a careful examination will nearly always show that a slight 
interval exists between the termination of the new flagellum and the 
side of the old one. As the flagellum grows longer the part already 
formed may stretch the common sheath and bring about its division, 
so that there are two undulating membranes in the earlier formed 
portion, while the distal extremity is still within the common sheath, 
and closely applied to the old flagellum. 
Eventually the filament connecting the two halves of the kineto¬ 
nucleus ruptures and the division is complete. The length and fineness 
of this connecting filament are Bemarkable. It retains the stain intensely 
showing up even after much extraction by the iron alum solution. 
