THE CONNECTION OF OXYGEN RESPIRATION QI 



the Pfliiger theory of the connection of anaerobic with normal 

 respiration presupposed a formation of easily oxidised sub- 

 stances in the absence of oxygen, Palladin followed the theory 

 of connection, at first without more closely defining his views 

 on the subject. Later he gave a detailed theory of respiration 

 which will be discussed in the next section. 



Maze^ assumes that alcoholic fermentation is the first stage 

 in oxygen respiration as well as in the assimilation of carbo- 

 hydrate by plants. This investigator seeks to demonstrate 

 that all the sugar consumed by normal respiration decomposes 

 into COo and ethyl alcohol in the process of alcoholic fermenta- 

 tion. The alcohol is assimilated by the absorption of molecular 

 oxygen and is not totally burned. In this way respiration and 

 structural change are represented as two inseparably connected 

 processes and all the carbon dioxide of respiration is formed by 

 the action of zymase. These far-reaching conclusions are not 

 sufficiently supported by Maze's experimental results. This 

 assumption is to be regarded as too weak to hold in the light of 

 modern discoveries, particularly in regard to the assimilation 

 of carbohydrate by way of the intermediate stage of ethyl 

 alcohol. This question will be more fully explained below. 



In his earlier work Kostychev- made the following assump- 

 tions in regard to the connection of oxygen respiration with 

 alcoholic fermentation. Alcohohc fermentation of itself is a 

 complicated process which consists of several stages. With 

 aerobic plants alcohol is formed only when oxygen is excluded — 

 hence in the absence of biochemical oxidation processes. A 

 complete oxidation of labile intermediate products of alcoholic 

 fermentation occurs with free access to oxygen before alcohol 

 is actually formed. In this way ethyl alcohol, contrary to the 

 assumption of Pfeffer and Wortmann, is not an intermediate 

 product of oxygen respiration but a metabolic product 

 which is spontaneously formed in strongly aerobic plants 

 only when oxidation is checked. Nevertheless an action 

 of zymase is indispensable for oxygen respiration because through 

 the action of enzymes of fermentation the sugar is changed into 



' Maze. Ann. de I'inst. Pasteur i6: 193, 346, 433- 1902; i8: 277, 378, 535. 1904. 

 - Kostytschew, S. Jour. f. exp. Landwirtsch. 2: 380. 1901. Russian; Untersuch. iiber 

 die anaerobe Atmung d. Pflanzen. 1907. Russian; and others. 



