7G6 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
lies against the cell-wall, in consequence of which its membrane in this 
position is not visible. The membrane in S. Ludwigii does not possess a 
firm and regular structure like those of other Saccharomycetes. The rest 
of the cell is filled with a cytoplasmatic network, the meshes of which 
are occasionally very fine and regular. The nodes of the meshes are 
usually pretty thick, and when the preparations are insufficiently and 
badly fixed they alone are stained. These are undoubtedly Eaum’s 
granules. Secretions of various kinds which form on the interior of the 
cell, and especially vacuolization, may alter and distort the typical form 
of the nucleus. Special devices must be employed to render the nucleus 
evident if the yeast have been starved by being kept in water. 
The sprouting of the Saccharomycetes takes place by kinetic division 
of the cells. This proposition is confirmed by several facts : — (1) By 
the cell-plate formed in S. Ludwigii , by the structure of the partition 
which eventually divides the mother-cell from the sprout, and by the 
peculiar structure which the cell-wall has at this spot after the two cells 
have separated. This place in the cell-wall which the author noticed also 
in the true Saccharomycetes is called by him the sterigmatic surface. 
(2) By the observation of the different phases of karyokinesis. The 
spindle-stage is peculiarly noteworthy, when the nucleus is pretty 
distant from the spot where the sprouting takes place, though it may be 
observed in other solutions. 
The appearances in spore formation were peculiarly interesting, the 
nucleus of the spores being formed by karyokinesis, during which process 
several distinct stages were observed. 
The author concludes his remarks by emphasizing the fact that the 
yeast-cell contains a nucleus, and this nucleus multiplies by karyokinesis 
(1) during sprouting and (2) during spore-formation. 
Two new Species of Saccharomyces closely allied to S. membranae- 
faciens.* — Upon fragments of the leaves of Euonymus eurojpseus which 
had been kept in spirit in order to get rid of the chlorophyll, Sig. P. 
Pichi discovered a species of Saccharomyces which did not set up 
fermentation. The author afterwards found a second species in the 
deposit from a “ vin des Cotes.” From further examination of these two 
species of Saccharomyces , and specially from their cultures in various 
solid and fluid media, the author was able to confirm the observation of 
Hansen who discovered that S. membransefaciens had no ferment power. 
The two new species agree in the main with Hansen’s species, but differ 
in some details, and the author separates them for the following reasons. 
S. membransefaciens ii. on Euonymus leaves : Asci usually oval or 
elliptical; spores usually three or four; diameter 3 /x, roundish, 
occasionally oblate. S. membransefaciens iii. : Asci spheroidal, oval, or 
elliptical; two, three, or four spores in each, with a diameter of 2*5 to 
3*5 fx. The cultivation results may be shortly expressed as follows: 
with S. membransefaciens iii. there is a copious development of asci 
during beer fermentation at 22°-25° ; with S. membransefaciens ii. very 
little. In artificial and wine-fermentation and beer-wort S. membranse- 
faciens ii. forms within 24 hours at 22°-25° a wrinkled milk-white scum. 
* Ann. Scuola di Viticolt. ed Enologia in Conegliano, Ser. iii. An. i. (1892). See 
Bot. Centralbl., liv. (1893) p. 9. 
