258 D. WARD CUTLER 
As will have been noted, throughout the whole of the divi- 
sion there is no development of spindle fibres, centrioles, or 
paradesmose. 
During the formation of the daughter nuclei the centro- 
blepharoplasts migrate from each other, carrying with them 
some of the flagella (Pl. 10, fig. 7). 
I have been unable to discover the origin of the remaining 
flagella or that of the suspensory threads to the nucleus. 
TEXT-FIG. 7. TEXT-FIG. 8. 
A slightly more advanced stage Early stage of nuclear division 
than the one shown in Text-fig. 5. with chromatin blocks resolved 
x 950; S.A., H.1.H. : into numerous small granules, 
x 900; 8.A. (D.J.), D.H. 
The actual division of the animal into two probably does not 
occur immediately after the formation of the daughter nuclei, 
for binucleate animals are commonly encountered in which 
the plasma shows no obvious sign of splitting. 
The division is, however, longitudinal, for the daughter 
centroblepharoplasts and nuclei always lie in a plane transverse 
to the axis of the body. This longitudinal division is a further 
indication of the flagellate relationship of P. pristina. 
‘GENERAL CONSIDERATIONS. 
Comparing P. pristina with the other species of Pseudo- 
trichonympha it is evident that, in many respects, it 
differs markedly from them. The species described by Hart- 
