ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
511 
principally intended to discover if there were any notable differences in 
their ferment action, and if so, whether any practical outcome were 
likely. Pure cultivations were made from ferments derived from 
various parts, and artificial must was inoculated with equal quantities at 
similar stages of development. The must was composed of extract of 
raisins to which had been added a definite quantity of tartaric acid and 
sugar. Erlenmayer’s flasks were used as cultivating vessels, and these 
were exposed to the same temperature conditions throughout. Every 
twelve hours the quantity of carbonic acid was estimated from the loss 
of weight, and at the end of fermentation the total quantity of alcohol 
and glycerin was determined. 
When the results were tabulated it was seen that the duration of 
fermentation varied according to the particular yeast from 17-32 days. 
The differences in the amount of carbonic acid formed were very slight, 
the maximum formation being attained in from two to three days. 
With regard to the quantity of alcohol produced by various yeasts, similar 
differences were observed, while those yeasts which had the shortest 
fermentation period produced the smallest amount of alcohol, and vice 
versa. Differences in the amount of glycerin formed conclusively 
indicate the specific differences of the yeasts used. 
Control experiments with natural must were made, the rest] of 
the experimental conditions being the same, and quite analogous 
results were obtained. The author concludes from his experiments that 
the number of races or kinds of Saccharomyces ellipsoideus is so great as 
not to be computable. 
Influence of Parasitic TJredineae on the Host-plant.* — Herr K. 
Fentzling describes the changes effected in a number of host-plants by 
parasites belonging to the genera Uromyces, Puccinia, Gymnosporangium, 
&c. The extent of the deformations are, in general, in proportion to 
the early period in life at which the host-plant is attacked. In external 
habit the effects are seen in the diminished height and branching, the 
smaller amount and size, but greater thickness of the leaves, the feebler 
development of wood, and the shorter life. In the leaves the epidermal 
cells are usually longer, intercellular spaces appear in the palisade- 
parenchyme, the spongy parenchyme increases in size, the cells becoming 
larger and more numerous, with intercellular spaces between them. In 
the stem the epidermal cells become longer, those of the cortical paren- 
chyme increase in number and size, there is a feebler development of 
wood, while the number of cells in the pith is larger. 
Hetercecious Uredinese. — Herr H. Klebahn j records the following 
observations on the life-history of various Uredinese. 
Gymnosporangium confusum occurs on Juniperus Sabina , and is gene- 
tically connected with an ascidio-form on Crataegus oxyacantha. Two 
species of Gymnosporangium are therefore parasitic on J. Sabina. 
Two new species of Peridermium are described, P. Stahlii and 
P. Plowrightii . From the former uredoforms were obtained on Alectoro- 
* ‘Morph, u. anatom. Unters. d. Veranderungen welcke bei einigen Pflanzen 
durch Rostpilze hervorgerufen werden,’ Freiburg-i.-B., 1892, 52 pp. See Bot. 
Centralbl., 1893, Beih., p. 83. Cf. this Journal, ante, p. 361. 
t Zeitscbr. f. Pflauzcnkrankkeiten, ii. (1892) pp. 91-5, 258-75, 332-43. 
