SACCHAROMYCES, 



371 



agar-agar it forms white porcelain-like colonies, and on potatoes 

 it yields broad, moist patches of a whitish-grey colour, soon 

 turning brown. In stab-cultures in gelatine, short bottle- 

 shaped growths develop from the point of inoculation 

 inwards. The cells are elliptical, 2-0 to 4-35/4 in length, and 

 1-5 to 2-9 JUL in breadth. 



When a solution of milk-sugar is inoculated in the presence 

 of calcium carbonate, and the product distilled, alcohol can be 

 detected. In a neutral 3 per cent, solution of milk-sugar, 

 JSaccharomyces acidi lactici yielded 0-108 per cent, of acid in 

 eight days. 



Saccharomyces fragilis Jorgensen (Figs. 79 and 80). 



While the budding and lactose-fermenting fungi found in 

 kephir, and described by others, do not form spores, a genuine 

 Saccharomyces has been discovered in the author's laboratory, 



Fig. 79. Saccharvmyees fragilis. Young growth in lactose Fig. 80. Saccharomyces 

 yeast-water (drawn by Holm from nature). fragilis Spore-formation 



(drawn by Holm from 

 nature) 



which has been called Saccharomyces fragilis, on account of 

 the feeble power of resistance of the cell- wall. 



The growth consists of relatively small, oval, and longish 

 ells (Fig. 79), with curious and feeble refraction. At 

 room temperature, this species behaves as a low-fermenta- 

 tion yeast. In cultures on gypsum blocks distinct spore- 

 formation begins in 20 hours at 25 C., and in 40 hours quite 

 .a number of free spores may be observed (Fig. 80) ; at 15 C. 

 the spore-formation takes place in about 40 hours. The bean 

 or kidney shape of the spores is characteristic. Spores are 

 also formed in growths in fermenting liquids and on gelatines, 



