658 



INTERNAL SECRETION ENDOCRINE GLANDS 



in causing dilatation of the pupil and retraction of the nictitating mem- 

 brane of the eye of a cat from which the superior cervical ganglion on 

 one side has bsen removed a week or two before the experiment. It is 

 well known that after this procedure these reactions are elicited by 

 adrenalin with great ease. 



Fig. 208. -Showing Spontaneous Liberation of Epinephrin in a Cat. 8 to 9, Pocket. 

 Epinephrin rise on release. Time-trace half-minutes (^ reduction). 



Or the adrenal vein blood can be collected directly from a cannula 

 in the cava pocket, and then tested on rabbit's uterus and intestine 

 segments (Fig. 209). 



Fig. 209. Intestine Segment Tracings with Adrenal Blood from a Cat. At 30, 

 Ringer's solution was replaced by indifferent (jugular vein) blood, and this at 31 

 by a specimen of adrenal vein blood collected during asphyxia. At 32, Ringer's 

 solution was replaced by jugular blood, and this at 33 by a specimen ff adrenal 

 vein blood collected previously without asphyxia. The bloods were diluted 

 with eight volumes of Ringer's solution. The concentration of epinephrin in 

 the specimens is seen to be about the same. Time, half-minutes (reduced to 

 two- thirds). 



The amount of epinephrin in the blood can be assayed by comparing 

 the effects produced by it with those produced by known amounts of 

 adrenalin. In such ways it has been shown that in cats the amount of 



