THE CONNECTION OF OXYGEN RESPIRATION 85 



Palladin's experiments formed only very small quantities of 

 CO2 in the absence of oxygen. After feeding them sugar the 

 rate of the anaerobic respiration of these leaves increased con- 

 siderably. On the basis of these results Palladin adopted the 

 view of Diakonow, so much the more because the former had 

 earher estabhshed without doubt^ the other facts brought out 

 by Diakonow to the effect that in the case of some plants I /N 

 is greater than i. At the time Palladin noticed that another 

 result of his experiments did not fit in the theory. The feeding 

 of sugar increased not only the anaerobic but also the normal 

 respiration of leaves to the same degree. The value of I/N 

 remained constant under all conditions. 



These results of Diakonow were decisive. Even Pfeffer 

 changed his views after the appearance of Diakonow's results. 

 In his second communication^ on the subject of anaerobic 

 respiration he takes into consideration Diakonow's results 

 which, though not yet published, were already known to him 

 because the work was done in his laboratory. PfefYer had by 

 this time given up his earlier views and speaks very vaguely 

 and ambiguously of the connection of anaerobic with normal 

 respiration. He states his new standpoint in the following 

 words: "These primary causes, which in normal respiration 

 bring about the oxidising action of oxygen, in the absence of 

 free oxygen show to advantage the prominent oxygen affini- 

 ties and hereby effect reactions {Umlagerungen) which pre- 

 viously did not take place wholly or in part, reactions out of 

 which arise carbonic acid as well as other products of intra- 

 molecular respiration." This is really a mild way of entirely 

 giving up the theory of connection. In fact it may be noted 

 that Pfeffer's position was very difficult. There had just been 

 carried out in his laboratory the investigations of Wilson and 

 Diakonow which contradicted his theory. In the second 

 edition of his textbook Pfeffer treats the whole question of 

 anaerobic respiration according to the results and conclusions 

 of Diakonow.^ 



1 Palladin, W. Bull, de la soc. des nat. de Moscou. 62: 44. 1886. Russian. 



2 Pfefifer, V/. Untersuch. aus d. bot. Inst. Tubingen i : 105. 1885. 



3 Pfeffer, W. Lehrb. d. Pflanzenphysiol. 2nd. ed. Vol. i. 1897. 



