206 STUDIES ox FERMEXTATIOX. 



mented liquids, have tlie power of becoming transformed into 

 actual alcoholic ferment. The result of those researches was 

 stated to be that these raycodermata do not become transformed 

 into ferment, properly so called, and that whenever any such 

 transformation has been supposed to have taken place, the 

 ferment produced was derived from germs introduced by the 

 air or by the utensils employed. What we did ascertain of 

 the ferment-producing power of mycodernia vini, was merely 

 that this plant, when submerged, is capable of causing sugar 

 to ferment, in consequence of a certain continuous life possible 

 to its cells, apart from the oxidations resulting from the 

 presence of free oxygen, but without any generation of new 

 cells taking place. 



Whilst engaged in these researches, we were pursuing others 

 in relation to the converse of the proposition just discussed, ■ 

 that is to say, respecting the possibility of ferment becoming 

 transformed into mycoderma viiii or mycodenna cereimice. Our 

 experiments in connection with this subject chiefly consisted 

 in various endeavours by way of exhausting the yeast and 

 subsequent revival of its growth. This exhaustion was eifected 

 by growing the yeast in excess of sweetened water, and at 

 other times in unsweetened yeast- water, our eiforts being directed 

 to deprive it of all power of fermenting. We afterwards 

 caused it to develop afresh in highh^ aerated, nutritious liquids, 

 in order that we might see how it reproduced itself, and if 

 its new form were that of a mycoderma. The yeast after 

 having lost its power as a ferment, and being no longer able 

 to act in pure sweetened water, nevertheless reproduced itself 

 when placed in fermentable media, holding in solution materials 

 adapted to its nutrition ; yet we never succeeded in obtaining 

 any organism besides the ferment, and, indeed, the identical 

 variety of ferment on which we had operated. In no case 

 was mycoderma vini or cerevisice produced, and we concluded that 

 we were justified in stating that whenever the mycoderma rini 

 appeared on the surface of a fermented or fermentable liquid, 

 its germ must have been introduced by the surrounding air, 



