462 Trypanosoma leivisi 
often invisible. In isolated flagella, which are sometimes to be found, the 
blepharoplast is nearly always present, the filament uniting flagellum 
and blepharoplast is very distinct in such cases. Minchin thinks that 
shrinkage, due to defective fixation, may separate the flagellum from the 
blepharoplast. If this connection were so delicate, one would never be 
able to find free flagella with their blepharoplasts, so I think this 
separation is due to some other cause. 
{d) The nucleus. The nuclear structure has already been described 
in my previous paper. Giemsa (1910) holds that the old method of 
fixation and staining does not show the minute nuclear structure. 
Diagram III, figs. 1, 20, 21 show the same structure as Giemsa 
described. It is very common in preparations made according to the 
old method. 
Diagram HI. 
Changes in the structure of the non-dividing nucleus. 
The structure of the nucleus is not so simple as that described by 
Moore, Breinl and Hindle. The simplest form shows a central karyo- 
somatic granule, united with the periphery of the nucleus by some achro¬ 
matic filaments (figs. 1, 21). This central chromatic mass can completely 
disappear, so that only a central achromatic structure remains (fig. 20). 
The karyosome may also be divided (figs. 2, 4, 6—-8) and the two parts 
may divide again (figs. 15, 16) or only one of them may divide (figs. 10, 
14). If no division takes place curious deformation of these granules is 
observable, due probably to the fact that the chromatin is spread 
over the achromatic reticulum, so that X- or H-shaped structures are 
produced (figs. 9, 11—13); at the end the chromatin is dispersed more 
or less completely over the achromatic filaments of the nucleus, so that 
these filaments become very distinct and the chromatin seems to be 
present in the form of rodlets or of a zigzag line (figs. 22, 23). A third 
