156 



MacDOUGAL and SPOEHR— components AND 



TABLE I. 



Hydration of Agar, Agar-albumin, Agar-gelatine and Gelatine in Terms 



OF Thickness and Volume. 



The data in the above table afford information on three main 

 questions, viz., the probable constitution of living matter to be in- 

 ferred from high hydration capacity, the nature of the colloids which 

 show a sensitiveness in hydration to the action of the hydrogen ion, 

 the hydroxyl ion and to ions which may be derived from amino- 

 compounds, and lastly the differentiations in heterotropic swelling. 



The highest swelling of the pentosan-protein mixtures is that of 

 agar i gelatine 3 in hundredth normal acid. Such colloids may be 

 present in the animal, but may be taken to be highly specialized or 

 unusual in the plant and not shown by the cell-masses of the vegeta- 

 tive tracts. Chief interest centers in the colloids in which the carbo- 

 hydrate and albuminous components each vary in forming 30 to 60 

 per cent, of the total and showing high hydration capacities in the 

 hydroxides, in glycocoll and in water. These mixtures furnish an 

 analogue of living matter of proved similarity of composition and 

 action. Not only has it been possible to compound biocolloids which 



