LIFE, CARBON^ OUTSTANDING PROPERTY 95 



like sugars and proteins, in the early oceans was possible 

 only because of the complete absence of life in them. In our 

 days this formation of organic matter would be impossible 

 since the countless microorganisms which are present every- 

 where would rapidly devour it. Complete absence of life 

 was therefore the prerequisite condition to give the lifeless 

 organic matter an opportunity to develop into the most 

 primitive living things during millions of years. Naturally 

 all forms of development intermediary between the simplest 

 lifeless organic substances and the simple living things have 

 been wiped from the earth, having served long ago as food 

 for the higher developed forms of life. 



So far it would seem that Oparin's investigations tend to 

 supplement and clarify our ideas about the gradual evolu- 

 tion of life from lifeless matter. Naturally there are also 

 some divergences of opinion concerning the detailed mecha- 

 nism of the origin of life from lifeless matter. In this respect, 

 Oparin does not attribute any importance to the self- 

 regenerating enzymes or to any form of life consisting of 

 single molecules. He stresses the fact that all the filtrable 

 viruses, which are the self -regenerating enzymes best known 

 so far, can grow only in living plants and animals. Their 

 cultivation on artificial nutritive media has not been defin- 

 itely proven although it has been reported by some experi- 

 menters. Doubt still prevails whether any mono-molecular 

 form of life is capable of developing outside of a host- 

 organism. For this reason Oparin does not seem to believe 

 in the possibility that self-regenerating enzymes could have 

 been the first forms of life to appear. 



Oparin even goes so far as to state that he cannot conceive 

 of an organism which is completely dispersed in its sur- 

 rounding medium. The term "completely dispersed" has 

 practically the same meaning as "consisting of only one 

 molecule or molecular aggregate" (so-called "micella"). 



