THE GENERA ZYGOSACCHAROMYCES, ETC. 285 



ring, but no film. Spores are produced, not only on gypsum 

 blocks, but also on various solid media containing wort, and 

 on dump bread, potatoes, ginger, &c. The limits of sporulation 

 temperature on gypsum blocks are 37-38 C. and 13 C. 

 The species ferments dextrose, Irevulose and saccharose, but not 

 maltose, lactose and dextrin. It was discovered in a vessel 

 containing ginger in Mayer's nutrient solution with saccharose. 



Zygosaccharomyces Priorianus, Klocker, was described provision- 

 ally by KLOCKER (IV.), without being named. The cells in 

 young wort cultures are of various forms, round, oval or elon- 

 gated, and firmly attached together so that the sedi mental yeast 

 forms a coherent mass. The largest cells are produced at i3-i6 

 C., which temperature is on the whole highly favourable to their 

 development, whereas at higher temperatures, e.g., above 27C., 

 many of them are very small, and at lower temperatures elongated 

 (sausage-shaped) cells are frequent. Old cultures often exhibit 

 very highly elongated, mycelial cells. The limits of temperature 

 for macroscopical development in wort are 36-38 C. and 3-8 C. 

 The colonies in plate cultures on wort-gelatin at room tempera- 

 ture occasionally resemble Peziza or lichens. At high tempera- 

 tures the surface of the colonies is smooth, but at 18 C. and 

 lower it is greatly wrinkled or convolute, and often yellow in 

 colour. Film formation is rare, but well-defined yeast rings are 

 often observed. The spores are round or oval, and generally 

 2-4 in a cell. At j6-i8 C. they form in large numbers on the 

 surface of the wort gelatin, on sterilised carrot slices, and on 

 gypsum blocks that have been immersed in wort instead of water. 

 In ordinary gypsum-block cultures, on the other hand, spores 

 are produced with difficulty if at all. The limits of sporulation 

 temperature on gypsum blocks in wort, and on slices of carrot, 

 are 27-28 C. and 3-9 C. The species ferments dextrose and 

 maltose, but not saccharose and lactose. It was discovered on 

 the bodies of honey-bees, and a similar or identical species has 

 been found on humble bees. 



In the genus Saccharomycodes, E. C. Hansen (XLIX.), the 

 spores, which are provided with only a single membrane, germi- 

 nate into a promycelium, and the new cells, produced from this 

 and the vegetative cells by budding, are incompletely separated, 

 a mycelium with well-defined septa being formed. Up to the 

 present two species are known : 



Saccharomycodes Ludwigii, E. C. Hansen. Synonyms : Ludwig's 

 Saccharomyces, E. C. HANSEN (XLVII.) = Saccharomyces Lud- 

 wigii, E. 6. Hansen (XVII., XLIV. and XL VIII.) = Saccharo- 

 mycodes Ludtvi</ii, E. C. Hansen (XLIX.). The species has been 

 illustrated by Hansen (XVII. and XLIV.), arid in.Figs. 146 and 

 150. The cells vary considerably in form, the lemon-shape pre- 

 dominating. The limits of budding temperature in yeast are 

 37-38 C. and i-3 0. Sporulation occurs not only on gypsum 



