208 



MICRO-ORGANISMS AND FERMENTATION. 



solution of saccharose, the cells may die within two years, 

 whilst most of the other Saccliaromycetes examined may be 

 preserved in this liquid for a much greater length of time. 



The maximum temperature for spore-formation is 32-32 JC.; 

 the minimum temperature 3-6 C. ; the optimum lies at 

 30-31 C. (18-20 hours). (NIELSEN.) 



Species of this type have frequently been isolated from 

 English and American apple-cider in the writer's laboratory. 



Closely allied with Saccharomyces Ludwigii are a number of 

 newly-discovered species, in which bud-formation has entirely 

 disappeared, propagation taking place only by division. 



^tP 



FIG. 61. Saccharomyces octosporus. Young vegetation after cultivation during 

 24 hours in beer-wort, at 25 C. (after SCHIOENNING). 



Saccharomyces (Schizosaccliaromyces) odosporus (Figs. 61, 

 62, 63), was discovered by BEIJERINCK on dried currants, 

 and has been more recently examined in the author's 

 laboratory by SCHIOENNING in growths on currants. The 

 propagation takes place in the following manner (Fig. 61): 

 About the middle of the cell a partition wall appears ; after 

 this has split up, the two new cells assume a round shape 

 and revolve round a point of the partition-wall, where 

 connection is still maintained, so that at last they lie 

 almost parallel. Finally, they separate entirely from each 

 other, having taken an ellipsoid or oval shape ; they then 

 expand in length, and the division begins afresh. But it may 



