THE SPIRAZINE STRUCTURE 



Growth and reproduction being the two indis- 

 pensible processes without which life is incon- 

 ceivable, the molecular structure of living matter 

 from which such life processes originate must 

 possess the two following characteristics: 



(1) It must be of such a nature that the process 

 of growth by assimilation of amino acid molecules 

 can take place continuously without producing 

 any sudden variation in its molecular configura- 

 tion or chemical behavior; and 



(2) It must be capable of division into a plu- 

 rality of portions each of which retains, either 

 actually or potentially, all the essential character- 

 istics of the original structure. 



Of the various geometric forms which molecu- 

 lar structures might exhibit, the helical spiral 

 appears to be about the only one which possesses 

 characteristics similar to those mentioned above, 

 and it appears that the helical spiral is also the 

 only configuration, besides rings and chains, 

 which the polypeptide molecule can be made 

 to assume. The ease with which diketopiperazine 

 rings are formed from dipeptides, and the diffi- 

 culty with which such rings are broken up, seems 

 to indicate that the valencies of the successive 



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