562 Transactions of the Canadian Institute. [Vol. VII. 



to the elements sodium, potassium, calcium and magnesium to the com- 

 position of sea water which obtained when all forms were unicellular, 

 just as the blood plasma owes its relations to the same four elements to 

 the composition of sea water which prevailed when circulatory fluids 

 were established. In other words the relation of protoplasm to salts is 

 due to the action for ages of sea water, for incalculably long periods of 

 time, on the living matter of unicellular organisms. 



