YEASTS AND MOULDS. 579 



Saccharomyces sphaericus. — Cells varying in form; the 

 basal ones of a colony oblong or cylindrical, 10 to 15 /a long, 

 5 /A thick ; the others, round, 5 to 6 /t in diam. United in ramified 

 families. Spores unknown. 



Saccharomyces anomalus (Hansen). — Cells small, oval, and 

 sometimes elongated. Spores are hemispherical, with projecting rims 

 at the base. They were found in impure brewery yeast. 



Saccharomyces mycoderma {Mycodprma cerevisim et mni). — 

 Cells oval, elliptical, or cylindrical, % to 1 ft. long, 2 to 3 yn thick, 

 united in richly-branching chains. Spore-forming cells may be 

 20 fjL long. Spores 1 to 4 in each mother-cell. The colonies in 

 gelatine are greyish and filmy. They form the so-called '' mould " 

 on fermented liqXiids, and develop on the surface without exciting 

 fermentation. When forced to grow submerged, a little alcohol is 

 produced, but the fungus soon dies. They occur on wine, beer, fruit- 

 juices and sauerkraut. 



Saccharomyces albicans {Oidium albicans, Fungus of thrush). 

 — Cells round, oval, or cylindrical, 3 -5 to 5 /j. thick ; the cylindrical 

 cells 10 to 20 times as long as they are thick. The bud- colonies 

 mostly consist of rows of cylindrical cells, from the ends of which 

 oval or round cells shoot out. Spores form singly in roundish cells. 

 In plate-cultivations the colonies are pure white. In the depth 

 of gelatine a filament is formed composed of white colonies, some 

 with ray-like processes extending into the gelatine. On potato the 

 fungus forms a rapid white growth, and on bread also. They 

 can be easily cultivated in a nutrient solution containing sugar 

 and ammonic tartrate. The cells germinate according to the rich- 

 ness of the fluid in sugar ; they either grow into long threads, 

 or, in a very strongly saccharine solution, many daughter-cells are 

 formed and bud out in various directions. According to Klemperer 

 the thrush-fungus is pathogenic in rabbits, death taking place 

 twenty-four to forty-eight hours after an intravenous injection of 

 a pure- culture. Long mycelial threads are found in the internal 

 organs. They occur on the mucous membrane of the mouth, 

 ■especially of infants, in greyish-white patches, which consist of 

 epithelium, bacteria, yeasts, and the mycelia of various moulds. 



Saccharomyces pyriformis (Marshall Ward). — Cells oval. 

 They convert saccharine solutions containing ginger into ginger- 

 beer. They occur with other micro-organisms in the so-called 

 " ginger-beer plant." 



Saccharom.yces glutinis. — Cells round, oval, or short 

 cylinders, 5 to 11 /u long, 4 /a wide, isolated, or united in twos. 



