72 Intracellular Salins [Sept. 



a number of important fonns, of which the following types seem 

 to be the niost common : 



1. Labile Compounds, consisting of moleciilar combinations 

 similar to glucose-sodium chloride, and atomic combinations, such 

 as sodium-proteinate. These Compounds readily undergo both 

 hydrolytic and electrolytic dissociation. 



2. Comparatively stable Compounds, consisting of inorganic 

 radicals and atoms incorporated in organic molecules, such as the 

 radicals of phosphoric acid in lecithins and the atoms of iron in 

 nucleoproteins. These Compounds do not appear to undergo hydro- 

 lytic dissociation. 



The " organic combinations of inorganic matter " are, as a class, 

 when compared with the simple salin constituents, less mobile, less 

 osmotic, and less prone to enter reactions in response to fluctuating 

 extracellular and intracellular conditions. 



That there are many types of adsorption products between in- 

 tracellular inorganic substances and colloids is obvious from the 

 work already done by many investigators. 



It is very probable that protoplasm consists of, or at least con- 

 tains, highly involved combinations of representatives of both the 

 simple and complex types of Compounds mentioned above. We 

 have very little definite chemical knowledge on this point, however. 

 The Story of the functions of the intracellular inorganic Compounds, 

 radicals and atoms, must be a long and instructive one, yet even 

 the introductory chapter of it cannot as yet be written with definite- 

 ness or satisfaction. 



III. INTRACELLULAR CARBOHYDRATES 



Ernest D. Clark 



The leaves of the higher plants contain the most efficient means 

 of changing the radiant energy of sun-light into the potential energy 

 of carbohydrate. The chloroplast of the plant cell is the primary 

 agent in this important process. The animal cell is essentially 

 a transformer of stored energy into work and heat. On that 

 account we should expect that the carbohydrates would not be plen- 

 tiful at any time in animal cells and that carbohydrates would not 

 long exist there in their original forms, although much carbohydrate 

 might be consumed in them. Such is the case, for in animals most 



