Fig. 1 . Unstained autoradiographs of kidney (upper rioht), uterus 

 (U, upper centre), and liver (L, lower). Low magnification. 



A light reaction is present in kidney and most of the uterus. A 

 pronounced reaction is present in liver tissues. The reaction is 

 minimal near the hepatic vein and portal veins, and maximal 



half way between the two. 



■'■■■^' ■-?'fe^- 



Fig. 2. Unstained autoradiograph of uterus. Higher magni- 

 fication. An intense reaction of the endometrium is apparent. 



To face page 10] 



