MODERN RESEARCHES INTO THE NATURE OF YEAST. 147 
The form best suited for observation was found to be a 
group consisting of a larger cylindrical cell, bearing at both 
ends several smaller oval ones. These were found in abun- 
dance in the scum on the surface of sauer-kraut, and were 
removed into a fresh nutrient fluid consisting of white wine, 
diluted with one half water, a drop of which was examined 
under the microscope. 
After from twelve to twenty-four hours, the cells put out 
a number of filaments, which were not unfrequently branched, 
and in which a septum soon made its appearance, the cell 
becoming bent at the spot where the partition-wall was formed, 
and breaking up into two cells. ‘The first bud appears after 
a time at the apex of the uppermost cell, in the form of a 
papilla, which in the course of an hour grows so rapidly in 
length and breadth as to equal or even exceed the parent- 
cell. A similar papilla then appears at the apex of the next 
lower cell, or the outer side of the bend, which develops 
Fire. 5. 
in the same manner; and by the repetition of this process 
the more or less regularly zigzag form so characteristic of the 
species is produced. 
The course of development is not always so simple as 
this, the cells themselves sometimes branching repeatedly, 
and producing a mycelium like that of mould still attached to 
the original parent-cell, the branches again ramifying in a 
complicated manner. 
The properties of the nutrient fluid appear to exert con- 
siderable influence on the development of the cells of the 
Mycoderma. Where the amount of nutriment is small, the 
filaments are usually short and not partitioned, the knee-lke 
bendings being also not developed; removal into a fresh 
nutrient fluid induces a new cycle of development. The 
arborescent form, which results from the production of a 
number of buds which do not become divided off by 
