Wager. — The Nucleus of the Yeast-Plant. 503 
that the body described by him can be regarded as a nucleus, 
and in fact he failed to discover it in all Yeast-cells. 
Moeller (’93) in a later communication points out that 
a better method of demonstrating the nucleus consists in 
boiling the cells in distilled water for one or two minutes, and 
then staining with haematoxylin by Heidenhain’s method. 
In yet another communication to a different journal (’93^) he 
gives an account of further observations which he has made 
to show that Krasser’s contention that a true nucleus is not 
present is not the correct one, and reiterates his statement 
that the vegetative cells contain a distinct nucleus. He also 
finds that the spores contain a similar body. In the forma- 
tion of the spore-nuclei, the mother-nucleus increases in size 
and becomes elongated and constricted. The ends separate 
from one another to opposite poles of the cell, the con- 
necting thread breaks through and disappears, and two 
daughter-nuclei are thus formed. The division is a direct 
one. In contradiction to his former statement he finds that 
true spores are formed in the mother-cell : but whether the 
Saccharomycetes belong to the Ascomycetes, and to the group 
Exoasci, appears not yet proved ; at present they must be 
regarded as genera incertae sedis. 
Hieronymus (’93) introduced another difficulty into the solu- 
tion of this vexed question by his discovery in Yeast-cells of 
a structure which he regards as similar to that which he has 
described for the Cyanophyceae. The protoplasm is full of 
angular granules which have a strong affinity for stains, and 
are so arranged that they form a thread interwoven in such 
a manner as to form a regular spiral or ball, which he calls 
the central thread. Sometimes this ball is located at one 
side of the cell, at others it expands and appears to pervade 
the whole of the cell ; sometimes it is found separated into 
two portions, one at each pole of the cell, connected together 
by a single row of these granules. During the process of 
budding a portion of this thread passes into the daughter- 
cell. 
Dr. A. Gortz, however, as quoted by Zimmermann (’93), 
M m 
