214 ABIOGENIC ORGANIC-CHEMICAL EVOLUTION 



On the basis o£ this reaction Ehrensvard considers that, in 

 a neutral or slightly alkaline medium in the presence of 

 hydrogen sulphide, (hcn)4 should be able to bring about 

 polymerisation, giving 



NHCHR.CS.NHCHR.CS.NHCHR.es 



NHCHR.CO.NHCHR.CO.NHCHR.CO 



If this were confirmed we should have a very interesting 

 scheme for the primary formation of polypeptides. 



Recently the Japanese scientist S. Akabori"^ has come 

 forward with extremely original and interesting ideas about 

 the problem with which we are concerned. 



As has been pointed out above, the synthesis of amino 

 acids in the primaeval atmosphere must have occurred in 

 accordance with the following equation 



R.CHO + NH3 + HCN^R.CHNHa-CN + HgO 

 R.CHNHo.CN + 2H,O^R.CHNH2.COOH + NH3 



Akabori put forward the suggestion that polymerisation was 

 not undergone by the amino acids themselves but by inter- 

 mediate products of the reaction. For example polyglycine 

 might be formed not from glycine but from aminoaceto- 

 nitrile : 



H2O 



nH2NCH2.CN->( — NHCHj.C — )„ >( — NHCH,.CO - )„ + nNHg 



II 

 NH 



This gets round the difficulty of the expenditure of energy 

 which stands in the way of the direct synthesis of polypeptides 

 from amino acids. Akabori considers that particles of silicates 

 or clay could have catalysed the polymerisation. As the cHj 

 groups of the polyglycine chain become more reactive during 

 this process, they are adsorbed on the surfaces of solid bodies. 

 Immediately after the polymerisation there occurs the con- 



