THEORY OF WORTMANN AND DELBRUCK 103 



the enzyme of respiration, the other is utilized for the maintenance 

 of the organism and the construction of new tissue. Zymase is then 

 an enzyme of digestion the same as amylase, maltase, etc. If, on the 

 contrary, the phenomenon takes place away from air some of the al- 

 cohol will remain unutilized, as is the case in the alcoholic fermentation 

 by yeasts. 



According to Duclaux, the term alcohol is not the simplest; by 

 means of the oxidases according to him it may be changed into the 

 aldehyde. Many have noticed the presence of alcohol in the product 

 of fermentation. It is known that aldehydes are generally considered 

 as the first step in the combination of H^O and CO2 in the green plant. 

 The yeast acts, then, exactly as a higher plant. It assimilates hydro- 

 carbon substances and forms formaldehyde as in the chlorophyll 

 synthesis. 



This theory is supported by a number of facts which are inter- 

 esting enough to cite at this time. Thus, Laborde has called attention 

 to a mold, Allescheria Gayoni (Eurotiopsis Gayoni)j which produces 

 zymase during a life very much more aerobic than that of the yeast 

 and which always gives a little alcohol in the presence of air which, 

 moreover, it uses for food. In Raulin's medium, in which alcohol is 

 substituted for sugar, the fungus vegetates very easily. Alcohol is, 

 then, a useful substance for it. It disappears in the form of water and 

 carbon dioxide with a rapidity comparable to that of carbohydrates. 

 The alcohol may be regarded as an intermediary product in the metab- 

 olism of the sugars. It is not apparent because it is used up as rap- 

 idly as it is formed. Quite recent experiments of Trillat and Sauton, 

 as well as those of Kayser and Demlon, have shown that after the 

 complete disappearance of sugar in wine, the yeast acts like any ordi- 

 nary cell. In presence of air it respires like ordinary plants by oxidizing 

 organic acids. It may oxidize the alcohol, and when agitated in the 

 presence of air, ethyl or acetic aldehydes may be formed by this oxi- 

 dation. It acts, then, like Allescheria Gayoni but in a more active 

 manner. On the other hand it has been known for a long time that 

 many of the Mycoderma, especially Mycoderma vini, and the myco- 

 yeast of Duclaux, are capable of maintaining themselves at the ex- 

 pense of alcohol. A. Perrier l has encountered a certain number of 

 microorganisms endowed with a considerable oxidizing power and in 

 particular capable of developing in a mineral medium containing ethyl 

 aldehyde as the source of carbon. This assembly of facts seems then 

 to prove that alcohol and aldehyde are able to represent two stages 

 in the assimilation of carbohydrates by plants. 



1 Perrier, A. Sur la combustion de Taldehyde ethylique par les vegetaux 

 inferieurs. Comp. Rend. Acad. Sciences, 151, 1910. 



