810 
Oriental Sore 
One is inclined to think that it is an indication of some intranuclear 
division centre though this has not actually been observed. In these 
flagellates the flagellum is generally traceable back to the kinetonucleus 
itself, and does not appear to rise from an extra nuclear blepharoplast 
as in many trypanosomes. It is possible that such a blepharoplast may 
be in some cases within the kinetonucleus and may be represented 
here by the pale staining portion of the kinetonucleus from which the 
flagellum is seen to arise. In division it would be obscured by the 
surrounding chromatin of the kinetonucleus though the fllaraent 
connecting the two halves is visible when the chromatin has divided 
and retracted from around the filament. In the division of the collar 
cells of Clathrina coriacea, so clearly described by Minchin and Robertson, 
the blepharoplast acting as an extra nuclear division centre takes on 
appearances very similar to these. The position of the blepharoplast 
outside the kinetonucleus as in trypanosomes of the blood, may be 
looked upon as a higher type of development while more primitive 
flagellates such as those under discussion, representing as they do 
flagellates of the intestinal tract of insects, display a more primitive 
condition with the blepharoplast within the nucleus. 
To return to the division of the cultural forms of the sore parasites, 
we find that very soon after the kinetonucleus shows signs of approaching 
division the karyosome of the nucleus becomes elongated and with it 
the nuclear membrane. The length of the karyosome increases, a con¬ 
striction appears and the karyosome may be divided into two parts 
(PI. XIII, fig. 6) at a comparatively early stage. More frequently however 
the two halves of the karyosome remain connected by a filament which 
may eventually stretch across the whole width of the parasite. At this 
stage the nuclear membrane is seen surrounding the ends of the elongated 
structure (PI. XIII, figs. 8, 10, 12,16). The appearance of the karyosome 
thus elongated resembles very much, though on a larger scale, the 
condition of the dividing kinetonucleus. The size of the chromatin 
mass at each end of the structure varies with the extent of the extrac¬ 
tion of the stain. The connecting filament however remains even after 
prolonged extraction (PI. XIII, fig. 2). 
It would appear that in the case of the nucleus also there is within 
the karyosome a division centre obscured by the chromatin, and in 
division represented bj^ the fine connecting filament, this filament being 
both in the case of the kinetonucleus and nucleus a centrodesmose 
corresponding to the centrodesmose described by Minchin and Robertson 
in the case of the division of the collar ceils of Clathrina coriacea. 
