396 TORULACE^E. 



containing nearly i per cent, of lactic acid with some species 

 formed a more favourable medium than neutral for most of the 

 species examined by myself. Lactomyces iti-flans caseiyrana, 

 Bochicchio, continued to vegitate in a broth containing 1-2 per 

 cent, of lactic acid, and Torula amara, Harrison, even in one with 

 2.4 per cent, of that acid. A few of the species described by 

 other workers, such as the Torula isolated from pine-apple by 

 E. KAYSER (V.) proved sensitive toward acids, as did also the so- 

 called Sacch. lactis and Sacch. tyrocola. All the species examined 

 by WILL (XXXII.) were able to stand direct treatment with a 

 4 per cent, solution of tartaric acid for forty-eight hours at 25 C. 

 (see p. 245, vol. ii.). 



Some species will even grow in alkaline media, Mei^sner's 

 muscinous yeasts developing as quickly in alkaline Liebig's meat 

 extract with sugar, as in wine must. On the other hand, the 

 budding fungi some of which at least must belong to the group 

 now under consideration discovered by 0. BAIL (I.) in decaying 

 rhubarb leaves, disappear when the reaction of the leaf mass 

 changes to neutral and alkaline. A series of budding fungi 

 capable of fermenting lactose, isolated by Maze,, induced a far 

 better fermentation in alkaline nutrient media than in those with 

 an acid reaction. Probably the alkali fixes the acids that are 

 liberated during fermentation and retards that process. 



Carbon dioxide retarded the development of Meissner's 

 mucinous yeast, without killing them, and the reproduction of 

 these organisms decreases as the alcohol content (see p. 239, vol. ii.) 

 of the nutrient liquid rises, ceasing when it reaches 9 per cent, in 

 must, though the cells do not die. The power of resistance is a 

 variable quantity. In the researches of WIRGIN (I.) reproduction 

 ceased in the case of a species of Torula, when the alcohol in the 

 grape-sugar broth reached 8.5 per cent., addition of ammonia 

 causing rapid reproduction. Sulphur dioxide also influenced the 

 activity and development of the said mucinous yeasts, about 

 o.i per cent, being the limit for hindering development. Tannin 

 restricted the growth and reproduction of the mucinous yeasts ; 

 and their resistance to acetic acid (see p. 246, vol. ii.) was very 

 slight. 



The temperature at which the known Torulacece continue to 

 reproduce occurs between wide limits, nearly all of them growing 

 even at 5-6 0. The intensity of reproduction varies consider- 

 ably, but is generally small at low temperatures, in which case, 

 moreover, the character of the nutrient solution greatly influences 

 development. Several of the species examined by myself remained 

 for a month without reproduction, in pure yeast beer at about 

 zero (1, though some of them grew, if only to a small extent, in 

 neutral saccharine yeast water ; and a few also in hopped beer 

 wort. With one of the species examined by HANSEN (LV.) ? the 

 minimum temperature was also 0.5 C. Sacch. lactis, Adametz, 



