5 1 6 Wager . — The Nucleus of the Yeast-Plant. 
in many cells there are two or more moving particles present. 
As fermentation proceeds these vacuoles disappear, and the 
protoplasm for a time appears homogeneous and clear ; but 
as the culture-solution becomes exhausted the contents 
become more granular, large brightly refractive fat-globules 
appear in it, the protoplasm contracts away from the cell- 
wall, the cell- membrane loses its turgescent appearance, and 
the whole cell presents an appearance of disintegration. 
Compressed Yeast-cells nearly always contain numerous 
brightly refractive granules. These are sometimes distributed 
regularly through the whole of the protoplasm ; sometimes 
they are located only around the vacuole, or more or less 
densely grouped together on one side of the cell. These 
are the granules which Hieronymus regards as of the nature 
of a nucleus, and are called by him the central thread. 
They increase in number when the cells are placed in 5 °/ o 
sugar-solution, and sometimes almost completely fill the cell. 
The vacuoles may, as in other Yeast-cells, contain one or 
two brightly refractive granules which exhibit a Brownian 
movement (see Figs. 33-40). 
The Nuclear Apparatus. 
By the term nuclear apparatus is meant that portion of 
the Yeast-cell which appears to be set apart to perform the 
function of the nucleus. 
According to Schmitz, Hansen, Strasburger, Moeller and 
others, the Yeast-plant possesses a nucleus of a simple 
structure consisting of a spherical homogeneous body placed 
on one side or near the centre of the cell. This body, which 
I propose for the present to call the nuclear body, can be 
very easily made visible by staining in methyl-green and 
fuchsin or in haematoxylin. To stain in methyl-green and 
fuchsin, a small quantity of fresh brewer’s Yeast which has 
been fixed and hardened according to the method of Moeller 
by means of iodine-solution, is spread thinly over a cover- 
