98 C. CLIFFORD DOBELL. 
division of the nucleus takes place in the manner just 
described. But in monads in a later stage of fusion small 
granules of chromatin can often be seen apparently emerging 
from the nucleus. At first these appear as little projections 
from the central chromatin mass; but later, as they become 
separated, they are seen as small granules attached by a 
slender stalk to the central mass (see fig. 25). Finally, they 
become completely separated, and degenerate in the cyto- 
plasm. ‘This process might also be described as a heteropolar 
division. It appears to occur in the organisms after the 
first reduction division has taken place, for the degenerate 
fragments of the first reduction nucleus are usually to be seen 
in the cytoplasm (see fig. 25). 
It is impossible to say whether a single reduction occurs 
in this manner, or whether more than one granule is extruded 
from the nucleus, on account of the fact that small broken-up 
bits of the first reduction nucleus are usually lying about in 
the cell. I can only say that at least one small nuclear mass 
is eliminated in this way. Personally I believe that only one 
granule is formed in each case, but I cannot prove that this is 
so, as I have never succeeded in watching the process in the 
living monad. 
By the time that the nuclear reductions are completed the 
two conjugants have become very largely fused with one 
another as regards the cytoplasm (fig. 26). The two reduced 
nuclei now approach one another, and the nuclear membranes 
come in contact. If the fate of the zygote is immediate 
encystment the flagellum is drawn in (fig. 28) and a cyst wall 
formed in the manner already described. Inside the cyst, 
therefore, one sees two nuclei in contact with one another, as 
shown in fig. 29. A process of fusion between the nuclei then 
takes place in the cyst (fig. 30), so that ultimately the cyst 
contains but a single nucleus (fig. 33). The nuclear mem- 
branes first break down at the point of contact, and the 
central chromatin masses finally fuse. When spherical the 
cysts have an average diameter of 7 u—8 pw. 
‘he nuclei come together and fuse in the same way in those 
