506 Wager . — The Nucleus of the Yeast-Plant. 
final conclusion arrived at by the author is that ‘ there is no 
nucleus, although such an organ may occur in other stages ’ 
which he has not been able to observe. 
Henneguy (’96) describes some observations made by him 
in 1886 on a red Yeast which had appeared accidentally 
among his cultures. This Yeast, which he examined in 
the fresh state and after being stained, exhibited very 
strongly a nucleus surrounded by a nuclear membrane and 
possessing a nucleolus. 
Crato (’96) shows that in an elongated Wine-Yeast which 
he examined, physodes are present with the protoplasmic 
network. On staining with iodine, a compact body which 
stains yellow is seen to be present ; this may be the 
nucleus. 
Buscalioni (’96), in his observations on Saccharomyces 
guttulatus , describes the division of the nucleus. The resting 
nucleus is a homogeneous body which divides directly by 
constriction whilst budding takes place. The two daughter- 
nuclei remain connected together by a thin filament until 
one of them has passed into ihe bud. A similar method 
of division is followed in the formation of spores. The latter 
differs slightly from the former, and may be regarded as 
a much reduced form of karyokinesis ; the former is a simple 
process of fragmentation. 
My own observations (’97) showed that in 5. Cerevisiae the 
nuclear body can be easily demonstrated by careful staining 
with haematoxylin, Hartog’s double stain of nigrosin and 
carmine, or aniline-water solution of gentian-violet. It 
appears to consist, in the majority of cases, of a homogeneous 
substance, spherical in shape, placed between the cell-wall 
and the vacuole. The process of budding in a Yeast-cell 
is accompanied by the division of this nuclear body into 
two. The division is a direct one, and does not take place 
in the mother-cell, but in the neck joining it to the daughter- 
cell. When about to divide, the nucleus places itself just at 
the opening of this neck, and proceeds to make its way 
through it into the daughter-cell, until about half of it has 
