ALCOHOLIC FERMENTS. 127 



mycetes which are distinguished by the mode of germination 

 or by the form of the spores. 



After a certain lapse of time, which varies with the different 

 species, roundish plasma-particles appear in the cells, and these 

 are the first indications of spores (Fig. 26). In their further 

 development, they become surrounded by a wall, which is seen 

 more or less distinctly in the different species. 



In the first type, to which Saccharomyces cerevisice I. 

 belongs, the spores can expand during the first stages of 

 germination to such an extent that the pressure which they 

 exert on each other whilst they are still enclosed in the 

 mother cell, brings about the formation of the so-called 

 partition walls (Fig. 27). This causes more or less plasma 



FIG. 27. 



Spores of Sacch. cerevisise I. in the first stages of germination, after Hansen : 

 at a, d, e, and g, formation of partition-walls ; at e, f, and g, the walls 

 of the mother cells have become ruptured ; at g a compound spore 

 divided into several chambers, the coherent wall is ruptured in three 

 places. 



to become squeezed or wedged between the spores, or the walls 

 of the spores may be brought into contact. During the further 

 development, a complete union of the walls may take place, so 

 that a true partition wall results ; the cell then becomes a 

 compound spore divided into several chambers. 



During germination (Fig. 28) the spores swell and the 

 wall of the mother-cell, which was originally moderately thick 

 and elastic, becomes stretched and consequently thinner. 

 Finally it becomes ruptured, and then remains as a loose or 

 shrivelled skin, partially covering the spores ; or it becomes 

 gradually dissolved during germination. 



