Wager . — The Nucleus of the Yeast-Plant. 505 
Eisenschitz (’95) raises a very interesting question : he finds 
that on cultivating Yeast for a day or two in beerwort 
coloured with methyl-green, congo-red, &c., the granules in 
the cell become stained. The granules are partly within and 
partly outside the vacuoles. The granules are of different 
chemical nature. The author thinks that the granules and 
vacuoles may be regarded as the preliminary stages of a 
nucleus. 
Macallum (’95) is inclined to regard the existence of 
a nucleus in the Yeast-cell, in its usual condition, as 
extremely doubtful, and supports Krasser’s view that nuclein 
is disseminated through the cytoplasm. On repeating 
Moeller’s experiments, and using this observer’s method, 
he found that now and then a structure such as is described 
by Moeller is present in Y. Cerevisiae ; but on comparing 
these preparations with others made by hardening and fixing 
in corrosive sublimate and staining with haematoxylin and 
eosin, he finds that this body is stained by the latter but not 
the former, and after fixation with Flemming’s fluid appears 
to have no particular affinity for any dye. In Ludwigii 
there is in the great majority of cells a corpuscle which 
corresponds with the nucleus of Moeller, but which behaves 
towards stains in a similar manner to the above. A substance 
like chromatin in its reaction to staining fluids appears to be 
disseminated through the protoplasm. The distribution of 
assimilated iron-compounds in these cells confirms these 
results. In .S'. Cerevisiae the assimilated iron is, like the 
substance which absorbs haematoxylin, distributed through 
the protoplasm, and sometimes in the latter in the form 
of granules. In Y. Ludwigii it is chiefly found at the^ 
periphery of each large vesicle when there are only a few 
of the latter ; but when they are numerous, the cytoplasm 
gives a uniform reaction for iron corresponding in its depth 
to that given with haematoxylin. There appears to be 
present also a substance which constitutes corpuscles of 
a nucleolar nature, which stain with eosin, and give a marked 
reaction for iron, but do not stain with haematoxylin. The 
Mm2 
