NATURE OF PROTOPLASMIC RESPIRATION. 339 



In this case a forked chain is produced, in which the carbon 

 atoms are attached directly. 



Moreover, from the aldehydes produced in the way indicated, 

 all manner of compounds will originate spontaneously, as Loew 

 has particularly pointed out. Thus from formaldehyde, formose 

 and the sugars spontaneously originate in faintly alkaline solu- 

 tions ; glycerine aldehyde goes over of itself into a hexose 

 sugar; acetic aldehyde in the presence of ammonium cyanide 

 forms propionic amido-nitril, which readily passes into amido 

 propionic acid or alanin, one of the most common constituents of 

 the albumins. The albumins themselves are nothing else, as 

 Kossel and Fischer have shown, than condensed amino acids. 

 This condensation, there is every reason to believe, can be 

 brought about by cell extracts, since from the kidney a sub- 

 stance has been isolated which brings about identically the same 

 kind of a condensation, namely, that of benzoic acid and glyco- 

 coll, to form hippuric acid. Finally, by spontaneous union of 

 the aldehydes with the cyanides found in so many cells, carbon 

 chains are built up readily outside the cell and presumably in 

 the cell also, since nitrils are not uncommon constituents of 

 protoplasm. 



Many other examples might be given here, but these will, I 

 think, indicate how completely the formation of substances found 

 in protoplasm can be accounted for by means of this fundamental 

 reaction which is going on. These syntheses and decompositions 

 must take place as a matter of course if the reaction is of the nature 

 sketched. I do not mean to imply that the amino acids, for ex- 

 ample originate altogether in the manner indicated. They may 

 also be formed by the union of oxyacids dissociated in Nef's 

 sense with NH 3 , without the intermediate formation of aldehydes 

 or ketones. Nef has shown that the lactates for example disso- 

 ciate as follows : 



CH 3 CH 3 



C< 



COOM COOM 



Lactate. 



If now NH 3 is present, union takes place directly with the 

 bivalent carbon atom. 



