u8 SCIENCE PROGRESS 



now connotes ideas no longer consistent with the facts, Barnes 

 proposed the terms aerobic and anaerobic energesis, to which 

 fermentative energesis might be added if necessary. 



Still further proof that the characteristics of living proto- 

 plasm are those of a reducing agent have been brought forward 

 by Loew and Bokorny 1 in their well-known endeavour to 

 establish a chemical difference between the living proteins and 

 " dead proteins." The active or living protein behaves as an 

 aldehyde and displays marked reducing powers. This latter 

 capacity is not, according to these authors, displayed by dead 

 protein. 



Finally as nearly conclusive proof that, in the plant at least, 

 uncombined oxygen has little or nothing to do with respiration, 

 it is to be noted that in plant respiration a direct relationship 

 between the concentration of the oxygen and of the carbonic 

 acid is directly demonstrable. In agreement with the law of 

 mass action, a high concentration (four to eight per cent.) 

 markedly lowers the respiration rate. 2 



On the other hand, any influence arising from a variation 

 in the partial pressure in oxygen is extremely difficult to 

 demonstrate. " Even in the higher plants," says Euler, " in 

 which chemical differentiation has been carried to the farthest 

 degree, a widespread indifference is to be found towards such a 

 variation, so that in many species respiration continues without 

 interruption even when the air contains only two per cent, of 

 oxygen (according to Stich) or indeed only one per cent, (accord- 

 ing to Johannsen). Equally indifferent are most plants towards 

 a notable increase of the oxygen concentration, so that the latter 

 may be increased by at least four or five times the normal amount 

 without producing any effect. And as Bert has shown bacteria 

 may endure simply enormous pressures " (Euler, I.e. p. 166). 



III. The Genetic Relationship of Anaerobic and Aerobic Life. — 

 If the simplest and most primitive of living organisms are 

 anaerobic ; if moreover the fundamental cellular metabolism be in 

 all cases essentially anaerobic and oxidation and combustion, as 

 it were, exterior or secondary processes ; if finally, our faith 

 in the reality of evolution be not somewhere lost in descending 

 the scale of life, then it must follow that there is a genetic 



1 Die chem. Ursache d. Lebens (Munchen, 1881); O. Loew, Die cJum. Energi 

 d. lebenden Zellen, 2te auf. (Stuttgart, 1906). 



2 Godlewski, Arb. hot. Inst. Wurzburg, v. 1, 1873. 



