502 Wager . — The Nucleus of the Yeast-Plant . 
finds that nuclein is present in Yeast-cells and was able 
to prepare and stain it. The granules do not appear to be 
concerned in any way with the process of budding or spore- 
formation. 
In opposition to these observations of Raum and Krasser 
we have those of Moeller (’92), who shows that each Yeast- 
cell possesses one nucleus. This is a homogeneous body 
which possesses neither membrane nor nucleolus, and is 
capable of changing its shape. Its position in the cell varies ; 
it may be central, or parietal, or at one of the poles of the 
cell. In the process of budding a portion of the nucleus 
makes its way from the parent cell through the opening into 
the bud. This then breaks off and rounds itself off as the 
nucleus of the newly formed cell. In order to observe the 
nucleus satisfactorily, the author makes use of cover-glass 
preparations fixed in a solution of iodine in potassium iodide. 
They are left in this solution for about twenty-four hours, 
then passed through water and dilute alcohol into absolute 
alcohol. Before staining they are soaked in saturated solu- 
tion of picric acid for some time, washed in water, and stained 
in an alkaline solution of baematoxylin, or in one of the 
aniline dyes, fuchsin, methylene-blue, &c. The preparations 
are finally washed in water, dried, and mounted. From an 
examination of the spores, Moeller comes to the conclusion 
that they do not possess either a nucleus or a nuclear mem- 
brane, and that in consequence they are not true spores. 
Mann ('’92) observed in actively budding Yeast-cells, after 
staining in Ehrlich’s acid haematoxylin, erythrosin, or eosin, 
a deeply stained granule which he supposes to be either 
a nucleolus or a nuclear chromosome. 
Krasser however (’93) states again that the cells of Yeast 
contain nuclein, but that it is not contained in the body 
described as a nucleus by Moeller. It appears to be dis- 
tributed in a finely divided form throughout the whole of the 
protoplasm. It is easily demonstrated macrochemically, but 
he finds considerable difficulty in demonstrating it by micro- 
chemical tests. He does not accept Moeller’s view therefore 
