54 



Scientific Proceedings (79). 



are also in the same direction ; the difference is only a quantitative 

 one and it is slight. Several years ago one of us (M.) reported 

 before this society that pituitrin acts strikingly different from 

 adrenalin upon the pupil of rabbits on the side in which the 

 superior cervical ganglion has been previously removed. We 

 have recently studied the subject from various angles and wish 

 to demonstrate the obtained results on these three rabbits. In 

 two of these animals the superior cervical ganglion has been 

 removed on one side several days ago ; the third rabbit is a normal 

 one. The demonstration shows the following facts. (1) The in- 

 travenous injection of pituitrin in a normal animal produces a 

 considerable constriction of the pupil, while adrenalin produces 

 a moderate dilatation of short duration. (2) The intravenous in- 

 jection of adrenalin causes a maximal dilatation of long duration 

 of the pupil on the side in which the ganglion was removed, while 

 injection of pituitrin causes rather a constriction. (3) When 

 adrenalin and pituitrin are injected simultaneously into a rabbit 

 in which a ganglion is removed the corresponding pupil dilates, 

 but the dilatation is much less than that of the pupil of a gangli- 

 onectomized animal which received adrenalin alone. 



Two facts stand out clearly: First, the effect of adrenalin upon 

 the pupil is dilatation, while that of pituitrin is constriction; 

 second, with regard to their action upon the pupil pituitrin 

 counteracts to a degree the dilating effect of adrenalin. 



34 (1212) 



Prolonged constriction of the bloodvessels by subcutaneous 

 injection of adrenalin into the ear of a rabbit. A 

 demonstration. 



By John Auer and S. J. Meltzer. 



[From the Department of Physiology and Pharmacology of the 

 Rockefeller Institute for Medical Research, New York.] 



Intravenous injection of adrenin causes a rise of blood pressure 

 which is due to a constriction of the bloodvessels. The rise lasts 

 only several minutes. The shortness of the duration of this rise 

 is explained by the escape of the injected adrenin from the circu- 



