ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
83 
cells aro elliptical or spherical, the latter averaging 4- 2 p in diameter, 
the former varying from 10 ■ 5 to 6 ■ 5 /i by 6 to 4 /x. They increase by 
budding ; no formation of spores could be detected. They do not invert 
cane-sugar like ordinary beer-yeast. They cause alcoholic fermentation 
in milk-sugar or lactose, and in dextrose, but not in cane-sugar or sac- 
charose. The bacteria are short cylindrical rods with homogeneous 
protoplasm, varying from 8 - 5 to 4‘5 /x in length by 0 - 8 p. in breadth ; 
by cultivation they develope into leptothrix-threads in which spores 
appear. They appear to take no part in the fermentation, remaining 
almost wholly in the zoogloea masses during the process. 
Red-coloured must-fermenting Yeast.* — Herr C. Kramer isolated 
by Hansen’s method, from the sediment formed during the fermentation 
of wine-must, a representative of the pink yeasts. Its cultivations were 
further examined in dextrose-gelaf.in. In 48 hours punotiform whitish 
colonies appeared, and these in about fourteen days became reddish. 
The cells of the yeast were usually round or oval, the vast majority having 
a diameter of 2 '7-3 -5 /x. Very large individual elements w r ere also 
noticed; these varied in breadth from 1' 5-2 ‘5 /x broad and 6-10 /x 
long. Combinations of more than three cells were rare. On solid media 
the colonies were apparently united into little masses by a gelatinous 
excretion easily soluble in water. Each cell is invested in a pretty 
strong membrane, and contains a round highly refracting body, giving 
with alcohol, ether, and osmic acid all the characteristic reactions of 
fat. 
From the absence of spore-formation (cultivation for a long time on 
gypsum blocks at 20° C.) the fungus showed that it was not a true 
blastomycete of the genus Saccharomyces. 
The red pigment, which only occurs on old cultivations, is easily 
soluble in water, but vanishes at once on addition of acid or alkali. 
In dextrose solution this pink yeast excites a lively alcoholic fermen- 
tation, and it seemingly belongs to the upper yeasts. The formation of 
alcohol by the yeast is quite considerable, for after eight days’ fermenta- 
tion at 25°, 4‘5 vols. per cent, could be demonstrated in 10 per cent, 
dextrose solution, the solution acquiring an agreeable must odour. 
In acid solutions the fermentation is more lively than in alkaline, an 
addition of 1*5 per cent, tartaric acid acting rather favourably than 
inhibitively on the fermentation and development of the fungus. With 
regard to the behaviour of the fungus to other kinds of sugar, it was 
ascertained that saccharose was inverted before fermentation, that maltose 
was fermented directly, and lactose not at all. 
Musk Fungus from Tree-sap.t — Prof. F. Ludwig has found on lime- 
trees a mucoid flux, which runs down the trees, having a dirty white or 
yellowish appearance and a gelatinous or cartilaginous consistence. On 
microscopical examination it was found that the predominating organisms 
were a fungus resembling Leptothrix and a Fusarium. After being cul- 
tivated on pepton-gelatin the Fusarium exhaled in about two days the 
* Oesterr. Landwirtlisch. Centralbl., i. (1891) pp. 30-45. See Centralbl. f. 
Eakteriol. u. Parasitenk., x. (1891 , pp. 124-5. 
t Centralbl. f. Bakteriol. u. Parasitenk., x. (1891) p. 214. Of. this Journal, 
1891, p. 784. 
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