114 STUDHi;? ON FERMENTATION. 



fixation of the oxygen of the air.* If, however, we suddenly 

 submerge the mycodemia, we shall obtain a different result. If, 

 on the one hand, the conditions of life of this fungus are 

 incompatible witli the altered circumstances in which it is 

 placed, the plant must perish, just as an animal does when 

 deprived of oxygen. But if, in spite of these changed condi- 

 tions of nutrition, it can still continue in life, we should expect 

 to see marked changes in its organic structure, or chemical 

 metamorphoses. The result of our observations points to the 

 continuance of life, in a distinct though sluggish and fugacious 

 activity, accompanied by the pheoomena of alcoholic fermenta- 

 tion, that is, the evolution of carbonic acid gas, and the pro- 

 duction of alcohol. 



If we take a drop of liquid charged with disjointed cells of 

 mycoderma, a day or two immediately after the submersion of 

 the film, we shall observe changes, small but appreciable, in the 

 aspect of a great number of these cells ; they will show increase 

 in size, their protoplasm will be in process of modification, and 

 many of them will have put forth little buds. It will be quite 

 evident, however, that these acts of interior nutrition and the 

 changes of tissue resulting from them, proceed with difficulty ; 

 the buds when they form will soon wither, and there will be no 

 multiplication of new cells. These changes will, nevertheless, 

 be accompanied by the decomposition of sugar into alcohol and 

 carbonic acid. 



In comparing these facts with those which we have pointed 

 out in connection with the cultivation of 2^€nicillii(m and asper- 

 gillus, we are compelled to admit that the production of alcohol 

 and carbonic acid gas from sugar — in one word, alcoholic fer- 

 mentation — is a chemical action, connected with the vegetable life 

 of cells which may difier greatly in their nature, and that it 

 takes place at the moment when these cells, ceasing to have the 

 power of freely consuming the materials of their nutrition by 

 respiratory processes — that is, by the absorption of free oxygen 



* See Pasteue, Oo77i2Jics rcndus des Seances de r Academic des Scie7ices, 

 t. liv., 1SG2, and t. Iv., 18G2. Etudes sur les Mi/codennes, &e. 



