34-6 A. P. MATHEWS. 



development is obvious. The substances produced from the 

 foods depend on the foods and not on the protoplasm. The so- 

 called organ-forming substances of the egg described by Whitman, 

 Lillie, Conklin and others, determine necessarily the character of 

 the protoplasm formed from them. There is but one other fac- 

 tor to be considered, i. c., the presence of catalyzers which may 

 accelerate different phases of a reaction. By this means a food 

 substance, undergoing in many different cells the same course of 

 transformation, will give rise in each to different proportions of 

 substances, depending upon what stage of its transformation is 

 accelerated. Thus, for example, a sugar undergoing one trans- 

 formation into alcohol, lactic acid and carbon dioxide, or other 

 substances may very readily give rise almost exclusively to lactic 

 acid, if the proper phase is accelerated. 



In this way, it is possible to see how the same foods in differ- 

 ent protoplasms will form substances which are present in the 

 different cells in widely different proportions. A specific instance 

 will make this clear. Amino-acids spontaneously split off the 

 amid group and form oxyacids. This occurs at a very slow rate 

 and is a reversible change. In the liver of mammals there is a 

 catalyzer which greatly accelerates this transformation. The re- 

 sult is that in this organ quantities of ammonia are produced 

 and a non-nitrogenous residue. In cells lacking this ferment, 

 this reaction goes on so slowly that there is no opportunity for 

 the accumulation and farther decomposition and recombination 

 of the products thus set free. Numerous other examples will 

 occur to all physiological chemists. 



In conclusion, I wish to point out that this conception is in 

 many important particulars only an application to some of the 

 problems of physiological chemistry of Nef 's theory of the nature 

 of organic chemical reactions. As will be seen from this paper, 

 I believe that his hypothesis of the spontaneous decomposition 

 of organic molecules with the formation of extremely reactive 

 dissociation products throws a new light on the chemical trans- 

 formations in protoplasm, and that many of those reactions become 

 clear at once if it be assumed that the reactive particles have the 

 properties of bivalent carbon. The importance of this theory for 

 physiological chemistry is not yet sufficiently recognized. 



