Wager . — The Nucleus of the Yeast-Plant. 531 
vacuole between it and the bud (Fig. 10). At first the young 
bud contains protoplasm only, but as development proceeds 
the nuclear vacuole begins to pass into it (Fig. 11). Then 
the nucleolus makes its way to the base of the opening 
of the mother-cell into the bud and at once begins to divide 
(Figs. 12-15). The vacuole at the same time divides. 
The products of division are unequal, the smaller portion is 
found in the daughter-cell, the larger portion in the mother- 
cell ; but both portions remain connected together for some 
time by a granular thread (Figs. 14-16, 18). The division 
of the nucleolus takes place in a very simple fashion either in 
the mother-cell or, as is more commonly the case, in the neck 
connecting it to the daughter-cell (Figs. 16-21). In the 
former case it becomes elongated, and constricted in the 
middle, finally separating into two equal or nearly equal 
portions, one of which then makes its way through the 
narrow neck into the daughter-cell (Figs. 19-21, 52). In 
the latter case the nucleolus puts out a projection into the 
narrow opening between the two cells which makes its way 
into the daughter-cell. When about half of it has passed 
through, division takes place and two equal portions are 
formed, one in the mother-cell, the other in the daughter-cell 
(Figs. 16, 17, 53). This method is the one more commonly 
found in 5 . Cerevisiae ; the other occurs more commonly in 
5 . Ludwigii and S. pastorianus, and occasionally in 5 . Cere- 
visiae also. As soon as the two nuclear bodies are separated 
from one another they move away to opposite ends of their 
respective cells (Fig. 18); the granular thread between the 
two vacuoles is broken, and the division of the nuclear 
apparatus is complete. 
When the nuclear vacuole is not present, the granular 
network in contact with the nucleolus undergoes a division 
into two more or less equal portions either in the mother-cell 
(Fig. 21) or in the neck joining it to the daughter-cell 
(Fig. 17); but in either case a granular thread is drawn out 
between them, and remains until all connexion between the 
two cells ceases. 
