222 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Fermentation of Cider.* — M. E. Kayser, in studying the fermenta- 
tion of cider, directed his attention in the first place to the chemical 
aspect of the different French ciders. Although these showed obvious 
differences of alcohol, tannin, sugar, glycerin, acids, &c., no results 
sufficiently definite for practical purposes were obtainable. Another 
object in view was to examine the various forms of fermentation-fungi. 
For this purpose 120 Pasteur’s flasks containing apple-juice were 
inoculated with single cells from pure cultivations. In the end the 
number was reduced to eleven species. In this examination the fol- 
lowing points were taken into consideration : the form and size of the 
cells, the surface scum and the bottom deposit, the sensibility of the 
vegetation to acid and alkaline sugar solutions. The clearness, taste, 
and odour of the resulting liquid were also noted. In examining the 
various kinds of Saccharomyces the author adopted a modification of the 
method introduced by Hansen; that is, noting the temperature-curves 
during spore-formation. This method is stated to have furnished excel- 
lent results. In another series of experiments the author made use of 
seven kinds of yeast, either alone or in mixtures, and, as far as possible, 
under conditions similar to those adopted in the commercial manufacture 
of cider. The results, as might be expected, were various, some being 
good, others indifferent, and others bad. The addition of Saccharomyces 
ajpiculatus imparted a perfumed bouquet. 
B. CRYPTOGrAMIA. 
Cryptogamia Vascularia. 
Selaginella lepidophylla.f — Herr W. P. Wojinowic describes the 
phenomena connected with the closing up and opening out of this plant 
under the influence of drought and moisture. It is a purely mechanical 
process, depending on its hygroscopic properties, and on the form of the 
primary axis of the plant, which is sympodial, forming a corkscrew- like 
spiral. 
Vascular Bundles of Isoetes.J — Sig. 0. Kruch describes in detail 
the histology and development of the conducting bundle in the leaves 
of Isoetes. It is collateral, and its phloem-portion consists of sieve- 
tubes and parenchymatous or cambiform elements, which generally 
become transformed, except at the base of the leaf, into mechanical ele- 
ments. The grouping of the sieve-tubes differs in the different species. 
Their longitudinal walls are distinctly thickened and punctated. The 
sieve-plate is covered by a substance which gives the reactions of callus. 
The xylem consists, in the limb of the leaf, of a system of canals 
bounded by cells of a special character, and of a parenchyme, in which 
some annular or spiral tracheids are dispersed. The bounding cells are 
of considerable width, and have very thin radial walls. As regards the 
* Anna! de l’lnstitut Pasteur, iv. (1890) p. 321. See Centralbl. f. Bakteriol. u. 
Parasitenk., viii. (1890) pp. 726-7. 
t Beitr. z. Morph. Anat. u. Biol. d. Selaginella lepidophylla, Breslau, 1890. See 
Flora, lxxiii. (1890) p. 501. 
X Nuov. Giom. Bot. Ital., xxii. (1890) pp. 396-402 ; and Malpighia, iv. (1890) 
pp. 56-82 (4 pis.). 
