ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
571 
of a membrane, a caryoplasm, and a nuclcolo. In the early stage of 
fermentation the nucleus becomes vacuolated, and shortly afterwards the 
protoplasm follows suit. When fixed at this stage, the nucleus is found 
to have returned to its original condition, while the protoplasm has 
acquired a characteristic and typical reticular appearance. 
Substances of nucleo-albuminous nature may be deposited in the 
protoplasmic portion, and may be so abundant as to form definite aggre- 
gates (granules). These granules always disappear before spore-forma- 
tion takes place. Yacuolisation of nucleus and cytoplasm may occur a 
second time in old cells. 
During budding of S. Ludivigii and Schizosaccharomyces octosporus, 
there is indirect division of the nucleus. In S. cerevisise and some 
others the division is direct. In the latter case, one of the nucleoles 
passes into the bud. 
In cells about to spore two nuclei are observable. These two bodies 
fuse together, and the resulting single nucleus contains about twice as 
much nuclein as the ordinary nucleus. Thus a fecundated ovum is 
produced. At the same time the granules disappear and the proto- 
plasm becomes profoundly altered. The new nucleus divides by a kind 
of very modified kinesis, though some of the stages are observable. In 
the second division similar, though still more modified, appearances are 
evident. 
During the maturation of the spores the nucleoles become invested 
with a membrane, and thus the nuclei are re-formed. During germina- 
tion, owing to the swelling of the spore, the nucleus becomes more 
evident. When the spore of Saccharomyces Ludivigii germinates, the 
nucleus passes into the promycele of Hansen. Sometimes the tw r o nuclei 
destined for fecundation do not fuse, and in this way false spores are 
produced which are sterile. 
Vitality of Alcoholic Ferments.* — Herr E. C. Hansen made a number 
of experiments and observations as to the vitality of alcoholic ferments 
kept in nutritive media and in the dry condition. The principal result 
of these investigations, which have been carried on for years, is that the 
greater number of the Saccharomycetes retain their vitality indefinitely 
in a 10 per cent, solution of saccharose, provided there be access of air' 
Much the same may be said for ferments resembling Saccharomyces and 
Mucor. 
Those which died were Saccharomyces Ludivigii , Carlsberg yeast 
number 2, the asporogenous variety of the latter, and Schizosaccharo- 
myces. 
In beer-wort, some of the yeasts were still alive after 10, 11, and 12 
years. In water, S. pastor ianus i. was alive after 11^ years, S. past or ianus 
iii. after 10 years, S. ellipsoideus after 10 years. 
The experiments on the dried cells were carried out on filter paper, 
cotton, and platinum wire. The cells on the filter papers were dead in 
less than 12 months ; of those on cotton, some were alive after 2 and 3 
years, but dead in less than 3 and 4 years ; while those on the platinum 
wires (dried in exsiccator) did not as a rule survive longer than a few 
* Resume du Compte-rendu d. Trav, d. Lab. de Carlsberg, iv. (1898) pp. 93-121 
(3 figs.). 
