414 



they constitute fresh cells. 2nd. By fissure, when the conditions 

 are not so favourable. If a drop of fermenting beer is watched 

 under the microscope, small granular bodies or nuclei are seen 

 inside the yeast cell ; by degrees this pinches in and splits up into 

 two to four cells. Within these mother cells are the spores or their 

 kernels, which are endowed with greater resisting power. 



The ferments of wine proper, S. ellipsoideus, also comprise 

 several families. Their optima temperature, i.e., that at which they 

 are in the full possession of all their energy, ranges also from 70 to 

 90deg. F. (22-32 C.) Below that temperature they are sluggish 

 and languid, above the higher one they are, after having passed 

 through a feverish period, left sickly and weakened. They[ are 

 elliptical in shape, and reproduce by sprouting. 



Saccharomyces pastorianus, ferment of secondary fermentation of wine 

 (greatly magnified.) 



There is also to be found in wine the 8. pastoriam^, which 

 compares with the elliptical yeast somewhat after the manner the 

 wild bee does with the high bred and industrious ligurian bee ; 

 even more, the S. pastorianus is more injurious than useful to wine, 

 and until the ermenting wine reaches 75deg. F. (24 C.) there is 

 always the danger of the elliptical yeast not being able to overcome 

 that particular mild yeast. 



In the spring when sweetish wines begin to work, it is this 

 yeast which is found mostly in the wine ; it likes a cool temperature, 



