206 
occur. The first consists in the unequal budding of the intra-nudeai 
centrosome, so as to form wliat appears as a small nucleus, which 
becomes pushed off towards the free portion of the flagellum. This 
little mass, which consists of a small portion of the intra-nuclear 
centrosome and a small portion of the outer nuclear substance, appears 
subsequently to simply disappear. The process we have just 
described undoubtedly corresponds to the similar production of a 
degenerating nuclear bud in T. cquiferdum. The second 
metamorphosis is constituted by the production of a body origina ting 
from the extra-nuclear centrosome. A portion of the substance of 
the extra-nuclear centrosome appears to pass round the adjacent 
vacuole, and to collect into a small mass on the side of the vacuole 
which faces the nucleus. 1 his soon becomes completely detached, 
and passes away toward tlie nucleus througli the cytoplasm. Dunng 
its development the detached body becomes larger, and the outer 
portion of it stains less densely, but it is often possible to see a darkly 
staining bead at the centre of tlie growing mass (figs. 8-Io). The body 
thus detached from the extra-nuclear centrosome may be found in all 
stages of transit from its original position to a close approximation to 
the nucleus (figs. 14-16). Having reached tliis latter position, it appears 
to remain for some time unchanged. The process here described in 
T. lewisi obviously corresponds to the similar detachment of a portion 
of the extra-nuclear centrosome, and its subsequent passage to the 
nucleus, which we have described in T. equiperdum. It also 
undoubtedly corresponds to the formation of the stainable band 
stretching between the extra-nuclear centrosome and the nucleus 
mg the life cycle of T. gatnbiense. The nucleus itself usually at 
tins penod begins to show signs of division. Such division which is 
presented in figs. iS-jg lakes place in a typical amitoticfasliion ; the 
mtra-nuclear centrosome dividing like a drop as in T. gambiense and 
r eqmperdum. and the outer nuclear substance collecting round the 
two derivatives in tlie same manner. 
y- 'J-- equiperdum, and T. cquinum, so also in 
/. /we have been absolutely unable to observe anything during 
he d.v.s.on of tl.e nude, or dunng uny other periods, whid. m the 
emc^test degree suggests the presence of chromosomes. Dunng 
fecomeVd K fu ‘ntra-nudear centrosome first elongates, then 
becomes dumb-bell shaped, and finally assumes the form of two large 
