ALCOHOLIC FERMENTS. 209 



also occur that two cells, still connected throughout the full 

 extent of the partition-wall, grow considerably longer, and form 

 fresh partition-walls, so that the original mother-cell appears 

 divided into four or more cells. Even at the beginning of the 

 fermentation in wort at 2 5 C., the cells form endospores ; but 

 the spore-formation is very inconsiderable, both under ordinary 

 fermentative conditions in wort and also during cultivation on 

 moist gypsum-blocks. This development is much more vigorous 

 on the surface of nutrient gelatines, such as wort-gelatine 

 (Fig. 62), where it forms round waxy colonies with a cavity in 

 the centre. The cells grow shorter and more rounded after 

 developing for some days at the temperature of the room, and 

 the ascus-formation, according to SCHIOENNING'S observations in 

 the Carlsberg laboratory, now takes place as follows (Fig. 62): 



FIG. 62. Saccharomyces octosporus. Development of the ascus (after SCHIOENNINO). 



The roundish cell grows longer ; a partition-wall appears, which 

 divides, after which the two new cells merely touch or are 

 contiguous at one point. Then they again coalesce (compare 

 the fusions observed by HANSEN in Sacch. Ludwigii), and 

 at last form a lengthened, ellipsoidal, hour-glass shaped or 

 irregular cell, which gradually increases in bulk, and within 

 which a varying number of spores (usually eight) are formed. 

 By degrees the wall of the mother-cell dissolves, and the spores 

 now lie embedded in slime, which subsequently disappears. 

 The spores are often oval, and according to LINDNER their 

 membrane is coloured blue by a solution of iodine in 

 potassium iodide. 



Both on the vegetative cells and on the asci of the spores 

 very slender lines may sometimes be observed, which form the 

 limit between the older, thicker parts of the cell-wall and the 

 newly-formed, thinner parts. The latter appear after the 

 partition- walls, which now form the terminal walls of the new 



o 



