530 Wager, —The Nucleus of the Yeast-Plant, 
As to the first alternative, the importance of the study 
of the cytology of the Yeast-Fungi and other low forms of 
Fungi as an aid in the elucidation of the very fascinating 
problem of the phylogeny of the nucleus need not be 
enlarged upon. There is in these lower forms a wide field 
of research open, which in the hands of a skilful chemist 
and cytologist may be very fruitful of results. 
The comparison which might be made between the nuclear 
apparatus of the Yeast-plant and that of some of the 
Infusoria is an obvious one, but it seems to be only a 
superficial resemblance. The terms c nucleus ’ and ‘ nucleolus ’ 
were rejected for the macro- and micro-nucleus of the Infusoria 
because they possessed neither the structure nor the physio- 
logical signification of the nucleolus and nucleus of ordinary 
cells (see Traite de Zool. Concrete, Delage and Herouard, 
1896, p. 410, tome i). On the other hand, as we have seen, 
the nuclear vacuole and nucleolus of the Yeast-plant can 
be very definitely compared to the nucleus and nucleolus 
of ordinary cells. 
The structure of the simple nuclear apparatus of the 
Yeast-cell may possibly afford some clue to the structure 
of the protoplast of the Bacteria and Cyanophyceae. The 
comparison, which may possibly be made of the central body 
of the latter with the nuclear body of Yeast, is at once 
apparent ; and the appearances often presented by the larger 
Bacteria when compared with such elongated forms as 
Y. my coderma , S, pastorianus, S. Ludwigii , are very striking. 
Budding. 
In the process of bud-formation, both the vacuole, when it 
is present, and the nucleolus take part. In those cases where 
the nuclear vacuole is not present, the granular network, or 
group of granules which represents it, takes part in the 
process. The former is found chiefly during the earlier stages 
of fermentation, the latter during the later stages. 
When the bud first appears on the mother-cell the nucleolus 
is found exactly on the opposite side of the cell with the 
