416 BOTANICAL GAZETTE [JUNE 
which stains intensely with the safranin in the triple stain. This 
body, or mass of bodies, seems to be composed of globules partly 
fused together, and has the position and presumably the function 
of the nucleolus in other plant cells. In this species of Closterium 
these bodies form an irregular accumulation at the center of the 
reticulum, usually, at least partially, fused together in various 
ways, sometimes in the form of a string of beads stretched across 
the long axis of the cell, while at the other times the chain may 
be coiled around on itself, so that it simulates a spireme or has 
the appearance of the chromatin in the cells of the salivary gland of 
the Chironomus larvae. As would naturally result from the partial 
fusion of spherical granules, the individual pieces are angular on 
some of their sides, while rounded on others. It is not possible 
to determine whether, in the living cells, these globules are separate 
or not, or whether the partial fusion is due to fixation, such as some- 
times happens in the case of chromosomes. Owing to the very 
faint stain which the reticulum takes and the very small size of its 
meshes, it is not possible to make out with any degree of certainty 
its relation to the central bodies. ‘ : 
In C. moniliferum (figs. 17, 18) the nucleus is composed, as 19 
c. Ehrenbergii, of a very delicate reticulum containing apparently 
very little chromatin in the form of granules. At the center of this 
reticulum is usually found a large, more or less angular body, which 
apparently represents the irregular mass found in C. Ehrenberg 
and the nucleolus of other plants. This nucleolus, while not having 
the smooth, homogeneous, globular appearance of that body = 
Spirogyra, still does not have the irregularly diffuse structure it 
presents in the other species of Closterium which I have studied. 
The pieces, while fused together, do not seem to form a compact 
mass. It has an irregular outline and shows lighter and darker 
places, if not stained too densely (fig. 17). The condition here 
would seem to represent an intermediate condition in the fusion of 
the nucleoli between that of Spirogyra and that of C. Ehrenbergit 
Prophase 
As the formation of the spireme apparently requires a long time 
for its completion, the prophase is one of the stages that ca” 
