210 C. CLIFFORD DOBELL. 
form of a spindle round the rodlet (fig. 6). I have never been 
able to make out achromatic spindle fibres at. this stage (cf. 
Trichomonas, p. 217, and fig. 21). 
At this stage, or perhaps earlier, the new flagella begin to 
make their appearance. They grow out from the thickened 
ends of the rodlet—which, from their subsequent development, 
IT shall now call the daughter blepharoplasts—as four (1. e. two 
from each blepharoplast) small peg-hke structures, which are 
easily recognised in Heidenhain preparations by their greater 
thickness and more intense staining. ‘They do not always 
appear simultaneously (see figs. 7, 8, etc.). One now 
notices that the chromatin masses itself together into a few 
large, irregular, very strongly-staining lumps, which he near 
the centre of the rodlet (fig. 7). The number of these masses 
varies, and they are usually difficult to count with accuracy. 
About six are present. They cannot justly be called chro- 
mosomes. It seems that the organism remains in this con- 
dition for some time, for it is the stage which is by far the 
inost frequently encountered in stained preparations. 
In a little while the chromatin heap becomes divided in two 
and each half travels along the rod, uniting the daughter- 
blepharoplasts, to take up a position by them (figs. 8, 9). 
he arrangement of the rod, blepharoplasts, chromatin masses 
and young flagellar outgrowths is particularly well seen in 
the specimen shown in fig. 9. 
When it has reached the region of the blepharoplast each 
chromatin mass fragments and constitutes a new nucleus (fig. 
10). During this process the rod becomes thicker and begins 
to stain less intensely (fig. 10). Hand in hand with the 
nuclear changes have gone changes also in the configuration 
of the cytoplasm. Whilst this was originally of a somewhat 
oval contour (figs. 4, 5), it passed through a stage of being 
roughly triangular (figs. 8, 9, etc.) to the present condition, 
which is more or less reniform in outline (fig. 10). 
For a long time I was unable to find any further stage than 
this in my permanent preparations, although I searched long 
and carefully. ‘The reason for this I then discovered from 
