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R. J. Harrison and J. L. D'Silva 



and 0-001 per cent of the total radioactivity at the 142nd 

 day of pregnancy. The average of all the estimations of the 

 activity of the chorion was one fifth of that of the placentome 

 15 minutes after injection. The R.P.A. of the membranous 



Table IV 



The Activity of Tissues in the Pregnant Goat 15 Minutes 

 after Intravenous Injection of 42 KC1 



1 Activity determined as shown in footnote to Table I. 



2 Potassium content expressed as mg. of K per g. of wet tissue 



chorion was considerably less than that of the placentome, 

 which suggests that the chorion exchanges its K at a slower 

 rate than the placentome. It is possible that this difference is 

 due to the lack of opportunity for exchange between the blood 

 and the cells of the chorion. 



