RED YEASTS AND BLACK YEASTS. 405 



tion of a gas, which forces the liquefied gelatin through the 

 colonies and scatters it over the surface, a number of cells being 

 carried off at the same time. Fischer and Brebeck, on the other 

 hand, attribute the appearance of secondary colonies to the 

 conidial cells being liberated by slight vibrations and then settling 

 down in the vicinity of the original colonies. 



The requirements of the red budding fungi in respect of 

 organic nutrient materials have not been specially investigated, 

 though it has been reported that starch paste forms a good 

 medium for certain species. According to HANSEN'S (LIV.) 

 researches, Elfving's red budding fungus will reproduce in purely 

 inorganic media, a fairly strong light being essential. Hence, in 

 this case at least, the red pigment plays an important part in the 

 physiology of nutrition, though the possibility of saprophytic 

 nutrition is not precluded. The red Torula of Janssens and 

 Mertens is also influenced by light, and behave like green plants, 

 respiration being also apparently more pronounced in the light 

 than in the dark. The researches of WENT (III.) with Manilla 

 sitophila in which the formation of carotin is dependent on light 

 indicate that the abundant production of carotin protects the 

 enzymes of the fungus from strong light. Little is known as to 

 the enzymes of the red budding fungi, though the action of cata- 

 lase was observed by HENNEBERG (V.). Fermentation is absent, 

 at least among the Mycoderma-like species of the second group, 

 and appears to be only imperfectly developed in the members of 

 the first group. E. Kramer's red budding fungus ferments 

 dextrose, maltose and saccharose, which it previously inverts, but 

 does not attack lactose. Fermentation for eight hours in sugar 

 solution furnished 4.5 per cent, of alcohol, by volume, the solu- 

 tion at the same time acquiring an agreeable fruity aroma, 

 indicating the formation of esters. The fermentation proceeded 

 more actively in acid media than in those with an alkaline reac- 

 tion, even 1.5 per cent, of tartaric acid being more stimulating 

 than restrictive. LINDNER (XXXY.) failed to obtain fermenta- 

 tion with any of the red yeasts examined. On the other band, 

 Kalanthar's greenish mazun yeast (p. 402, vol. ii.) possesses 

 fermentative power. 



Yery little has been published on the behaviour of the red 

 budding fungi toward acids. The red Torula of Janssens and 

 Mertens produces only small quantities of acids, which are 

 exclusively non-volatile. 



The optimum temperature of growth is about 20 C., as with 

 many species of Torula. The vital activity of Janssens' and 

 Mertens' red Torula is impaired by a temperature of 30 C. A 

 red Torula, isolated by SCHMIDT-NIELSEN (I.) from the surface of 

 the deep-water shrimp (Pandalus borealis] furnishes a luxuriant 

 culture on potato slices in fifty to sixty days at zero C. E. 

 Kayser's pink yeast withstands heating to 45 C. in the damp state. 



