MODERN RESEARCHES INTO THE NATURE OF YEAST, 145 
Prof. J. Cienkowski has made an important contribu- 
tion to our knowledge of the fungi connected with various 
fermentations.' The old theory, that yeast owes its origin 
to various species of mould—notwithstanding Reess’s care- 
ful investigations—was still constantly cropping up, and was 
supported by such facts as the yeast-like outgrowths from 
the mycelium of Dematium pullulans and from the ger- 
minating filaments of Taphrina and Ezxobasidium, as well as 
the existence of similar structures as the gemme of Mucor 
and conidia generally. In the midst of these facts it would, 
indeed, seem very strange if Saccharomyces were the only 
organism of the kind that carries on an independent existence, 
and is not rather anelement in the cycle ofdevelopment of some 
form of mycelium-producing fungi. In order to determine the 
question, Cienkowski has carried out a series of experiments 
on the development of Mycoderma vini, Desm., which agrees 
in most of its phenomena with beer-yeast, and which can be 
easily cultivated quite free from admixture. 
The white pellicle which rapidly forms on the surface of 
the most diverse organic fluids—urine, beer, milk, fruit-juice, 
sauer-kraut, cucumber-juice, infusions of roots, &c.—consists 
mainly of two essential ingredients, Mycederma  vini, 
ine, 8} 
Desm. (fig. 3), and Oidium lactis, Fres., often accompanied 
by a branched mycelium, bearing at its septa single 
conidia or groups of them, and easily breaking up into 
separate cells ; for this organism he proposes the name Cha- 
lara Mycoderma'! (fig. 4). In the present paper he traces 
the development chiefly of the Mycoderma and Chalara. 
The cells of Mycoderma are most commonly connected into 
an arborescent form, each cell putting out a young “ bud” from 
its apex, and subsequently a younger one from each side of 
‘ Bonorden (‘Handbuch der Mycologie,’ p. 36, t. i, fig. 27) has given 
this name to a structure which, judging from his figure, is apparently the 
mycelium of Ocdium lactis. 
