DISTRIBUTION OF ORGANIC SUBSTANCES 1 15 



the original form of life and more complicated forms have 

 evolved from them. 



As early as 1922 I expressed the view that all the difficulties 

 and contradictions which have been discussed were only 

 apparent and that the first living things to develop on the 

 Earth were quite able to nourish themselves heterotrophi- 

 cally on organic substances because these compounds must 

 have been formed abiogenically on the Earth long before 

 the appearance of life on it/^ The belief that organic sub- 

 stances could only be formed biogenically under natural 

 conditions was based on a preconception of the conditions 

 which prevailed on the Earth at the appropriate epoch in 

 its existence. If, however, we take a broader view of the 

 question and extend our studies beyond the limits of our 

 own planet to include facts concerning other heavenly bodies, 

 then this conception will be rudely shaken. 



The distribution of organic substances 

 (hydrocarbons) on different 

 heavenly bodies. 



Spectroscopic studies of the atmosphere of the stars have 

 long ago shown that carbon is very widely distributed 

 throughout the universe. It is to be found everywhere. It 

 has been shown recently that this element plays an extremely 

 important part in the life of stars. It is well known that 

 the source of stellar energy resides in particular reactions 

 taking place within the nuclei of atoms and that these take 

 place in the interior of the stars where temperatures of some 

 tens of millions of degrees prevail. Under these conditions 

 hydrogen is converted into helium with a resulting decrease 

 in mass and consequently with the release of enormous 

 amounts of intra-atomic energy. 



H. A. Bethe'*^ states that reactions of this kind can only 

 take place in the presence of carbon which acts in a peculiar 

 way as a ' catalyst ' in this nuclear reaction. In the course 

 of this four hydrogen nuclei (protons) are converted into 

 helium with the liberation of a very large amount of intra- 

 atomic energy. 



This so-called carbon cycle is the fundamental cause of 

 the shining of the stars which is therefore directly associated 



