SACCHAROMYCETACEAE }4S 



ascus parthenogeneticallv, or it may fuse with another similar cell 

 before ascospores are developed. 



Ahxelium is lackins^ in nearly all yeasts, but on srelatin Schizo- 

 sac char oniyces hidivigii forms hyphae, as does Sac char oiiiyces 

 p077ibe when grown on beer w^ort. Hansen observed that 5. cere- 

 visiae, the cultivated yeast, formed ascospores on gypsum or clay 

 blocks if good aeration was provided, the temperature and hu- 

 midity were favorable, suitable food was available, and the cells 

 were young. Other important species of Saccharomyces include 

 S. ellipsoideiis, a ^\■ine yeast; S. pirijorviis, the ginger-beer yeast 

 that lives symbiotically with Bacterhnu vennifonne; and S. sake, 

 which saccharifies rice starch to make sake. 



Schizosaccharomy ces octosponis, occurring commonly on iigs 

 and raisins, conjugates within 10 to 12 hours if cultivated on 

 sterilized carrot or potato or on sucrose agar. Pairs of cells form 

 short tubes that unite. The 2 nuclei fuse within the canal formed 

 by these tubes, and the canal then broadens until the structure is 

 dumbbell- or barrel-shaped. Meantime 3 nuclear divisions have 

 taken place, and soon 8 ascospores are delimited. Saccharoiityces 

 p077ibe, used in the fermentation of millet to make African beer, 

 and S. viellacei, used in the manufacture of Jamaica rum, may 

 reproduce in the same manner as Schizosaccharomy ces octo- 

 sporiis, or may form ascospores parthenogenetically. Pic hi a 

 mandshiiriciis is used in the fermentation of sorgho, and another 

 species is concerned in the manufacture of pulque from the juice 

 of decapitated maguey {Agave spp.) plants. Willi a anormtla is 

 one of the beer-wort yeasts. 



In Nematospora the ascospores are long and needle-shaped and 

 are formed in 2 groups of 4, a group in either end of the ascus. 

 Each ascospore is provided with a long whip-like appendage. 

 Three species of some economic importance have been described, 

 N. coryli from hazel nuts, N. ly coper si ci from tomato fruits 

 [Schneider (1916)], and N. phaseoU from beans [Wingard 

 (1925)]. 



LITERATURE CITED 



Brefeld, O., "Die Hemiasci und die Ascomyceten," Untersuch. Gescnmut. 



MykoL, 9: 1-156, 1891. 

 Dodge, C. W., Medical mycology. 900 pp. C. V. Mosby Co., St. Louis. 



1935. 



