CHAPTER LX. 

 MYCODERMA. 



BY PROF. DR. RICHARD MEISSNER, 



Principal of the Royal Wiirtemberg Institute for 



Viticulture at Weinsberg. 



302. Species of Myeoderma. 



THE film yeasts (see pp. 120 and 387, vol. ii.) comprise numerous 

 species, of which comparatively few have, as yet, been thoroughly 

 examined. They are all unicellular budding fungi, which repro- 

 duce either by budding and sporulation, or by budding only, and 

 are therefore in part true Saccharomycetes of the genera Pichia 

 and Willia (see pp. 287 and 289, vol. ii.), and in part non-Saccharo- 

 mycetes. The latter may be divided into three groups, two of which 

 belong to the Torulacece (p. 386, vol. ii.), the third comprising the 

 various typical species of Myeoderma. These last alone will be 

 treated in the present chapter to the exclusion of such species as 

 were regarded as Myeoderma by earlier workers, but must be 

 allocated to the pink yeasts or Torulacece on account of their 

 fermentative power, oval cell form, or other peculiarities. These 

 excluded forms comprise, for example : Heinze's Myeoderma 

 (Tucumerina, Aderhold; the Myeoderma species mentioned by 

 Lasche, Myc. rubrum, Lasche's Myc. humuli, Henneberg's two 

 Myeoderma species, and the sporogenic film yeasts of Fischer and 

 Brebeck. It may be mentioned here that the Torulacece and 

 Myeoderma species have a number of properties in common ; 

 their distinguishing characteristics will be found on p. 385, vol. ii. 

 To the Myeoderma species belong, inter alia, a species of film 

 yeast examined by WILL (XIII.) ; certain film yeasts described 

 by MEISSNER (XI.) ; others described by Hansen, A. Petersen, 

 Gronlund, Jorgensen, Lindner, Prior, Belohoubek, Kukla, Forti, 

 Seifert, Lafar, Koch, Wortmann, E. Rist and J. Khoury, and 

 others. Like the true wine yeasts, these various species of Myeo- 

 derma have their natural habitat in the soil, from whence, as 

 shown by the researches of Hansen, Miiller-Thurgau and Wort- 

 mann, they are conveyed to their appropriate nutrient solution 

 by insects, rain or wind. 



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