524 Wager. — The Nucleus of the Yeast- Plant. 
vacuole ; this has the appearance of a nucleolus, but is not 
to be distinguished by its staining properties from the other 
substance in the vacuole, and its shape is also irregular in 
many cases, although it often is distinctly spherical. The 
network structure of many or most of the vacuoles recalls 
very distinctly the structure of the nucleus in the higher 
plants in the resting stage (Fig. 4), and its reaction towards 
stain is distinctly comparable to this also, although somewhat 
masked by the deeply stainable character of the protoplasm. 
The contents of the vacuole seem to contain a considerable 
amount of chromatin, as shown by its reaction towards stains, 
especially methyl-green, and its insolubility in digestive fluid. 
In some cells all the chromatin-substance appears to reside 
in the vacuole, in others it is diffused through the protoplasm, 
and in some cells it appears in the nuclear body. The first 
condition is found in young, actively-growing cells three or 
four hours after fermentation. 
The nuclear vacuole may persist but a short time as such. 
At quite an early stage in the fermentation we find several 
cells in which a distinct vacuole is not to be seen, but only 
a granular network in contact with the nuclear body; and 
as fermentation proceeds still further, the vacuole disappears 
from nearly all the cells, leaving only this irregular granular 
network in contact with the nuclear body. On staining in 
methyl-green and eosin, both the nuclear body and the 
granular network around it are now found to stain intensely 
green or blue, apparently indicating that a portion of the 
green-staining substance has been taken up into the nuclear 
body (Figs. 21-27). The nuclear body at this stage is 
generally found closely pressed to the cell-wall by the mass 
of glycogen which has appeared in the cell as a result of an 
abundant supply of nutriment (Fig. 25). 
With methyl-green and fuchsin, the nuclear body at this 
stage still stains red, but with a slight tinge of blue in most 
cases, and the granular substance in close proximity to it 
stains blue. The other contents of the cell stain pink. The 
granules are sometimes placed in a more or less regular 
