142 MYCOLOGY 



Guillermond/ who suggests the probable evolution of such forms from 

 Eretnascus and Endomyces. Dr. H. Will discusses in Lafar's book 

 the family Torulace^e, species of which are widely disseminated on 

 field and garden fruits and on plants of all kinds finding suitable condi- 

 tions for their growth during the decay of these fruits, and during the 

 technic processes of fruit preservation, such as the making of pickles 

 and sauerkraut. A number of them will no doubt prove to be budding 

 stages of other fungi for our knowledge of them is decidedly imperfect. 

 The character of the so-called pink yeast, red yeast, and black yeast is 

 even less well known. As they are budding fungi, some have even 

 classed them with the genus Saccharomyces. The genus Mycoderma 

 was created to include the budding fungi, which form true films and 

 which are formed rapidly on nutrient liquids, particularly on beer 

 and wine with air between the cells, which are usually short and sau- 

 sage-shaped. They are strongly aerobic and form, when exposed to 

 the air, a wrinkled skin on the surface of the liquid. Like the true wine 

 yeasts, these various species of Mycoderma have their natural habitat 

 in the soil and they are carried to their appropriate nutrient substances 

 by insects, rain or wind. They are probably not true yeast plants, but 

 may represent growth conditions of other fungi, as related to certain 

 nutrient materials. Curious chemic activities are possessed by species 

 of Mycoderma, for example, the formation of acids and their destruc- 

 tion both at the same time. Citric and succinic acids for example are 

 consumed by them. 



1 GuiLLEEMOND, M. A.: Rcchetches Cytologiques et Taxonomiques sur les 

 Endomycetees. Revue Generale de Botanique, 21: 401-419, 1909. 



