278 ORIGIN OF ANAEROBIOSIS 



event with the secondary loss of eyes in many cave 

 animals. 



On the whole, the present author is inclined to believe 

 with Koschtojanz (1935, 1935a) that both the anaerobic 

 and the aerobic metabolism should be regarded as original 

 traits of true animal life. The various degrees of develop- 

 ment of anaerobic functions in the members of the contem- 

 porary fauna offer no objection to such an assumption. 

 Both types of metabolic processes are coupled more or less 

 closely with each other, and with a variety of secondary 

 processes {e.g., various methods of waste removal). The 

 balance struck between the various combinations of re- 

 actions seems to decide to what degree a certain animal 

 species is dependent or independent of molecular oxygen. 



