536 Wager. — The Nucleus of the Yeast-Plant . 
the details of the division is, however, so great that one must 
be very cautious in attempting an explanation of the facts 
observed. 
Summary. 
It may be useful to give here a short summary of the 
conclusions at which we have arrived as a result of this 
investigation. 
1. All cells of Yeast contain a nuclear apparatus. 
2 . In the earlier stages of fermentation this consists of 
a nucleolus in close contact with a vacuole which contains a 
granular chromatin-network, and exhibits a structure in many 
cases like the chromatin-network of the nuclei of higher 
plants. 
3. In the later stages of fermentation the chromatin- 
containing vacuole may disappear, its place being taken 
by a granular network or a number of chromatin-granules, 
which may be disseminated through the protoplasm or grouped 
around the nucleolus. 
4. The nucleolus is present in all cells. It appears to be 
a perfectly homogeneous body, which may, however, at times 
appear granular owing to the granules around it. 
5. In young cells numerous chromatin-vacuoles are often 
found. These appear to fuse together to form the single 
vacuole which occurs in cells during the early and sometimes 
later stages of fermentation. 
6. In the process of budding, the division of the nuclear 
apparatus does not exhibit any definite stages of karyokinesis. 
It must, I think, be regarded as a direct division of the nucle- 
olus into two equal or nearly equal parts, accompanied by 
division of the chromatin-vacuole, network, or granules. 
7. The nucleolus divides either in the neck joining the 
bud to the mother-cell, or more rarely in the mother- cell 
itself, one of the products of division passing subsequently 
into the bud. 
8. In spore-formation, the chromatin disseminated through 
the protoplasm becomes absorbed more or less completely 
