85 



protoplasm during the transplantation into a fresh culture-fluid (pre- 

 paration to the division of the cell etc.). 



I have mjself repeatedly made microscopic preparations in different 

 phases of the fermentation. In a beer-yeast, kept for two weeks 

 under 10 perc. cane-sugar, I found along with volutin-free cells 

 many with one or more coarse volutin-granules, also a few with a 

 great number of scattered fine granules. When they were incubated 

 in a phosphate-free fluid, fermentation set in at once. After 20 

 minutes (1 c.c. fall of the mercury-column) the same picture was 

 seen under the microscope as before the fermentation. After 1 hour 

 (fall of the mercury-column 2 c.c.) some cells had begun to germinate. 

 They were obviously richer in coarse volutin-granules than the other 

 cells. The bridge between the knob and the mother-cell was also 

 stained deep blue. Just as in this case the cells in a volutin-containing 

 culture generally exhibit a picture differing so much the one from 

 the other that, in my judgment, it is impracticable to point out a 

 distinct change in connection with the fermentation. True, with the 

 Torula monosa in a fresh phosphate-containing culture-fluid faint- 

 violet coloured vacuoles, which have generated after a long incuba- 

 tion in the same malt-agar medium, are often seen to disappear, 

 but there is nothing whatever that points to a correlation with 

 fermentation. On the contrary, what goes very much against such 

 a correlation with the fermentation as such, in the case of Torula 

 monosa, is the discovery that when these yeast-cells are incubated 

 with a fluid containing 2.5 perc. lactose instead of 2.5 perc. glycose 

 (along with peptone, MgSO^ and KNO3) exactly the same picture is 

 presented by the spreading volutin-granules in the coverslip-prepara- 

 tions, made during some hours. Now it is well-known that Torula 

 monosa, as the very name indicates, attacks exclusively monose not 

 lactose. In a similar way I examined at the same time the beer- 

 yeast-culture mentioned above, which had been incubated under 

 10 perc. cane-sugar, as well with 2.5 perc. lactose as with 5 perc. 

 glycose (both with an equal amount of peptone, MgSO^ and KNOg). 

 Fermentation-experiments taught that, as might be expected, only in 

 the latter case an evolution of carbonic acid occurred, since lactose 

 is not fermented. A convincing difference between the yeast-cells in 

 these two fluids was not noticeable. True, after 1, 2, and 3 hours 

 a more diffuse dissemination of the volutin-granules was to be seen 

 in part of the^ cells, but only in a very small percentage of the 

 cells, which was perhaps a little higher in the glycose-containing 

 fluid. The difference was, however, not such as to point to a close 

 relation to the fermentation. 



