30 Can Science Explain Life? 



The two ends of such a spirazine will be differ- 

 ent in that one end will be formed of an acid 

 carboxyl group whereas the other end will be 

 formed of a basic amino group. When the dis- 

 similarity of chemical structure at the two ends 

 is taken into consideration, it seems highly im- 

 probable that the ability to grow by assimilation 

 of amino acid molecules could be possessed by 

 both ends alike. The fact that the physiological 

 effects of different substances when injected into 

 the blood stream are due almost entirely to the 

 positive kations seems to indicate that assimila- 

 tion in animal cells takes place at the carboxyl 

 ends only, although the acid character of the 

 chemically active portions of living matter may 

 also be due to phosphoric acid radicles clinging to 

 the amino groups at either end of the spirazine, 

 and acting catalytically as intermediaries to facili- 

 tate the assimilation of amino acid molecules, just 

 like sulphuric acid acts catalytically to facilitate 

 the combination of alcohols with organic acids to 

 form esters. The fact that phosphorus occurs 

 principally in the nuclear materials where such 

 assimilation is known to take place, and even 

 there only in comparatively small amounts, seems 

 to indicate that it does not enter permanently into 

 the interior of the chemical structure of proto- 



