Age Changes in Red Blood Cells 



201 



the red cell electrolytes may change with age. The subject 

 was taken up by Hallman and Karvonen (1949) in another 

 species, sheep. A distinct difference between foetal and 

 adult Finnish sheep was observed, in the sense that the con- 

 centration of potassium in erythrocytes was higher in foetal 

 than in adult sheep. Fig. 1 shows the differences in both 



50 100 



Sodium millieq. per litre 



Fig. 1. The concentration of potassium and sodium in the 

 erythrocytes of sheep foetuses (F) and their mothers (M) 

 belonging to the Finnish breed (Hallman and Karvonen, 

 1949). The corresponding figures for the red blood cells of 

 adult sheep of other breeds fall along the two straight lines 

 (Evans, 1957). 



sodium and potassium concentrations. The sum of the two 

 electrolytes tends to remain constant with age. 



Widdas (1954) confirmed this observation and found a 

 gradual decrease of the potassium and an increase of the 

 sodium with advancing foetal age. 



The study by Hallman and Karvonen (1949) brought out 

 another interesting finding. In 1898 Abderhalden published 



