130 The Living Plant 



much light upon some of the most fundamental problems of Bi- 

 ology. 



Class VIII. Living Protoplasm 



This substance is of such importance and complexity as to re- 

 quire for its treatment, a separate chapter, which follows. It 

 need only be said in this connection that so far as chemical 

 analysis has been able to penetrate into the mysteries of living 

 protoplasm, it appears to be merely a very complicated mixture 

 of proteins with many simpler substances. Here for example 

 is a list of the substances which have been recognized in a chemical 

 analysis of the protoplasm of one of the lower plants; — 



Water, Pepsin and Myosin, Vitellin, Plastin, Guanin, Xanthin, 

 Sarkin, Amnionic carbonate, Asparagin and other amides, Pepton 

 and Peptonoid, Lecithin, Glycogen, Aethalium sugar, Calcic com- 

 pounds of higher fatty acids. Calcic formate. Calcic acetate, Calcic 

 carbonate, Sodic chloride, Hydropotassic phosphate, Iron phosphate, 

 Ammonio-magnesic phosphate, Tricalcic phosphate. Calcic oxalate, 

 Cholesterin, Fatty acids extracted by ether, Resinous matter, Glycerin, 

 coloring matter, etc.. Undetermined matters. 



In this list, which I give in order to illustrate the chemical 

 complexity of protoplasm, all of the constituents are well-known 

 substances, no one of which has any of the properties of life, 

 unless such a substance lies hidden in the trifling amount of "Un- 

 determined matters" ; nor has any chemist yet been able to identify 

 any distinctive living substance, — any of that protoplasm par 

 excellence which we are logically bound to believe must exist. 

 But the further consideration of this subject belongs with the 

 next chapter. 



Such are the groups of substances which plants build upon the 

 foundation laid by the photosynthate. We may summarize their 

 relationship in a diagrammatic manner, after the analogy of a tree 

 of ascent, as shown herewith. 



