468 
Tnipanosoma leivisi 
tioning that in stages like hgs. 3-—5 it is not uncommon to see the 
karyosome very distinctly in one half of the nucleus, whereas it is 
invisible in the other half. 
Type (i) (figs. 7, 8). Here the nucleus becomes C'lually elongated 
(fig. 7) and in the centre a structure may be seen resembling the 
karyosome of fig. 1, only it is achromatic. Whether this structure must 
be considered as a karyosome which has lost its chromatin, or simply as 
Diagram VIII. 
Figs. 1—6. Nuclear division with karyosome. 
Figs. 7—8. Nuclear division without karyosome. 
Fig. 9. Pseudomitosis. 
a part of the achromatic reticulum I do not know. In fig. 8 (nucleus on 
the left hand) the last stage of division is represented. The two 
daughter nuclei are already separated but still linked together by a 
filament uniting the two central achromatic structures. All the 
chromatin is situated at the periphery. 
If this central achromatic structure is only a part of the achromatic 
reticulum supporting the chromatin, I seriously doubt whether a 
karyo.some does really exist in the nucleus of T. leivisi. The figures of 
Diagrams III and VIII seem to indicate that the chromatin may wander 
