THE CONNECTION OF OXYGEN RESPIRATION 83 



increase in the production of CO2 is to be expected when oxygen 

 is admitted, since the intermediate products formed in consider- 

 able quantity in the absence of oxygen should burn vigorously 

 with renewed access to oxygen. The author carried out only 

 one experiment with an elder branch and observed no increased 

 production of COo after leaving it for a time in a chamber free 

 of oxygen. That this kind of increase in the respiratory energy 

 does in fact often take place will be clear from later descriptions. 



Godlewski^ expressed his opinion that the absorption of 

 oxygen and the release of CO2 in oxygen respiration constitute 

 a uniform process and require no prehminary step to true 

 respiration. Reinke' follows this view entirely and assumes 

 that the respiratory material is burned directly to CO2 and 

 H2O by the activity of powerful catalysts which activate the 

 atmospheric oxygen. 



It is evident that the theory of the connection of anaerobic 

 with normal respiration met with Httle approval in plant phys- 

 iology. Only Pfeffer and Wortmann declared themselves in 

 favor of it but their schematic representations proved to be 

 unsound. When Diakonow next came forward with his refined 

 experimental studies the fate of the "Theory of Connection" 

 was decided for a considerable time. Diakonow's results are 

 incompatible with the assumption of a connection of anaerobic 

 with normal respiration for the following reason. If anaerobic 

 respiration is a prehminary step to the normal process, it must 

 meet all the conditions of nutrition under which normal respira- 

 tion continues unhindered. If this is not the case it must be 

 concluded that normal respiration can take place without the 

 participation of material transformations which are only pos- 

 sible in the absence of oxygen under certain conditions. Diako- 

 now really sought to prove that normal oxygen respiration 

 continues under conditions which preclude anaerobic respiration. 



The interesting experiments of Diakonow^ were carried out 

 with pure cultures of the molds, Penicillium glaucum, Aspergillus 

 niger and Rhizopus nigricans. The experimental method con- 



1 Godlewski, E. Jahrb. f. wiss. Bot. 13 : 524. 1882. 



2 Reinke, J. Bot. Zeitg. 1883 : 65. 



3 Diakonow, N. Arch, slaves de biol. i : 531. 1886; 4: 3i. 121. 1887; Ber. d. bot. Ges. 

 4:1. 1886. 



