532 Wager . — The Nucleus of the Yeast-Plant . 
The granules which thus pass into the young bud seem to 
develop in some way into the small vacuoles often found in 
young cells, by the fusion of which the single large vacuole is 
formed. 
Spore-Formation. 
The following is a very easy method of obtaining spores. 
Fresh compressed Yeast is placed in a dilute sugar-solution 
(about 5 °/ 0 ) in an ordinary glass tumbler, and left to ferment 
at the ordinary summer temperature of a room. The surface 
of the liquid soon becomes covered with a scum, due to the 
fermentation at once set up, part of which is left sticking to 
the sides of the glass as the liquid evaporates. In the course 
of forty-eight hours the cells in the scum on the side of the 
glass begin to sporulate, and at the end of three days a large 
number of cells are obtained with spores in all stages of 
development. The method is a simple one, and has never 
failed to produce spores in large numbers. Spores are also 
easily obtained when a thin layer of compressed Yeast is 
spread over blotting-paper which has been soaked in 5°/ o 
sugar-solution, and kept moist in a shallow dish covered by 
a glass plate. The sugar-solution seems to induce the forma- 
tion of spores more freely than the plaster slabs soaked in 
water. 
The spores can be easily demonstrated by staining cover- 
glass preparations in fuchsin as recommended for the spores 
of Bacteria. This stains only the ripe spores. The immature 
spores can be made visible by subsequent staining in a dilute 
aqueous solution of methylene-blue. In successful prepara- 
tions the ripe spores are red, unripe spores blue, and the 
protoplasm light red. 
The changes which take place in the cell, leading up to the 
formation of the spores, can be observed in fresh living cells, 
but it is necessary to stain them very carefully to observe the 
details of the process. The two best stains for the purpose 
are the combination carmine and nigrosin, and the solution of 
gentian-violet in aniline-water. Other stains have been found 
