328 NON-SACCHAROMYCETES OR DOUBTFUL YEASTS 



other two yeasts and yeast 4 more quickly than 7. These four yeasts 

 ferment dextrose and levulose. The fermentation continues for a 

 long time with yeasts 4 and 7, longer than with the other two. The 

 temperature limits for budding for these four yeasts are below 4 C. 

 and 34-35 C. Yeasts 1 and 3 are more resistant to alcohol (ethyl) 

 than the other two. Will considers yeasts 1 and 2 as two varieties 

 of the same species which he designates under the name of Pseudosac- 

 charomyces cerevisiae and yeasts 4 and 7 as varieties of another species 

 to which he gives the name of Pseudosaccharomyces vini. 



TORULA NIGRA. Marpmann * 

 Syn.: SACCHAROMYCES NIGER. Marpmann 



This species was isolated from milk by Marpmann. It was re- 

 garded by this author as related to P. membranaefaciens. The cells 

 are round or oval (1.5 to 3.0 ju in diameter). In sugar solutions, no 

 mycelium is produced. On gelatin as in other substrates, black 

 colonies are formed. This yeast does not seem to utilize saccharose 

 and lactose but it uses a small quantity of dextrose. It seems to se- 

 crete either maltose, lactase, amylase, inulase, or invertase. Hansen 2 

 has shown that this yeast does not form ascospores and consequently 

 does not resemble P. membranaefaciens. It is related to the genus 

 Dematium. Guilliermond 3 has confirmed the opinion of Hansen and 

 shown that this species possesses characteristics which class it with 

 the Dematium. He has shown that on carrot it produces, at the end 

 of 24 hours, a sticky mass composed of oval, slightly elongated cells, 

 clothed with a sort of mucus which contains black particles. These 

 are without doubt the black pigment seen in cultures. After a few 

 days there is formed at the less moist parts of the carrot culture a 

 very slender mycelium, which rises from the black mass of the yeasts. 

 According to the investigations of Guilliermond the yeasts of this 

 fungus include only a single nucleus and have a structure analogous 

 to that of true yeasts, but the units of the mycelium may enclose 

 many nuclei. 



Hansen has observed two black Torula related to Torula nigra. 

 Lindner has also described a black Torula cultured' in Koch's labora- 



1 Marpmann, G. Cent, allgemeine' Gewidlets Richard Landw. Jahrbucher, 

 1891. 



2 Hansen, E. C. Ueber rot und schwarzgefarbte Sprosspilze. Allg. Grauer- 

 und Hopfenzeitung. 1887. 



3 Guilliermond, A. Recherches cytologiques sur les levures et quelques 

 moisissures a forme levures. Thesis for the Doctorate at the Sorbonne. Rev. 

 generate Botanique, 15, 1903. 



