Wager.— The Nucleus of the Yeast-Plant. 525 
group on one side of the nuclear body, sometimes they 
surround it on all sides, and occasionally they are found 
distributed through the protoplasm (Figs. 21-27). In these 
older cells of Yeast, where the nucleus is restricted to the 
cell-wall by the large glycogen-vacuole, the nuclear body 
is sometimes surrounded by a vacuolar network in which 
granules may or may not occur (Fig. 26). This vacuolar 
network is sometimes very regularly placed around the 
nuclear body, which then looks as if surrounded by a halo, 
and has occasionally given rise to a false interpretation of its 
structure. This was especially well seen in some specimens 
of 5 . Cerevisiae , Hansen I, which had been sent to me in 
corrosive sublimate solution by Dr. Hansen (Fig. 26). 
On treating fresh Yeast with digestive fluid (pepsin-glycerin) 
for twenty-four hours, a reduction in the stainable cell-contents 
is observed. In many cells a somewhat large, irregular 
granular mass is the only portion which stains deeply ; in 
others, two or sometimes three such masses are observed, all 
connected together by deeply-stained granular strands. I was 
at first much puzzled by this, as no nuclear body was visible ; 
but on repeating the experiment with a more careful staining, 
I found the nuclear body reduced in size and masked by the 
more deeply-stained granules around it. The granular 
substance in contact with the nuclear body varies much in 
size and shape, and is sometimes at some distance away 
from it, but is always connected with it by means of deeply- 
stained strands. The nuclear body stains much less deeply 
than this granular mass, and there seems to be no doubt that 
the latter consists of the much contracted and in part disin- 
tegrated nuclear vacuole. In older cells in which the nuclear 
apparatus had become restricted to the wall of the cell by the 
glycogen-vacuole, the whole mass — nuclear body and granules 
— stained the same green-blue colour in methyl-green and 
eosin and of the same intensity, an indication that at this 
stage in the development of the cell a considerable portion 
of the chromatin is taken up into the nuclear body. 
In S. Ludwigii and S. pastorianus the structure of the 
