Influence of Infundibular Hypophysis upon Pupil. 103 



toxicity of strychnin is definitely reduced not only when it is 

 administered in great dilution, but also when saline or water is 

 administered nearly simultaneously in other parts of the body, 

 thus, perhaps, diluting the poison within the circulation. These 

 results are of general theoretical interest and have obviously 

 also a practical bearing, neither of which we shall discuss here. 



74 (683) 



The influence of the infundibular portion of the hypophysis 



upon the pupil. 



By S. J. MELTZER. 



[From the Department of Physiology and Pharmacology of the 

 Rockefeller Institute.] 



The action of the extract of the hypophysis is similar to that 

 of adrenal extract in the first place by the influence which both 

 exert upon blood pressure. There seems to be also some similarity 

 in their action upon the uterus and intestines. With regard to 

 the action of hypophysis upon the frog's pupil which, as is well 

 known, becomes definitely dilated by adrenalin, opinions differ. 

 While Cramer and others report a dilatation, Kepinowand Gottlieb 

 recently stated that in their hands the extract of the hypophysis 

 caused a constriction of the frog's pupil. In my own observations 

 upon the enucleated bulbi from Rana pipiens, heated and un- 

 heated pituitrin (Parke Davis & Co., prepared from the infun- 

 dibular portion of the hypophysis) in most instances caused a dilata- 

 tion of the pupil. The extent of the dilatation varied greatly in 

 various eyes and was never as striking as is observed under the 

 influence of adrenalin. In a smaller number no dilatation of the 

 pupils took place ; but in no instance have I observed a miosis follow- 

 ing the bathing of the bulbi in pituitrin. 



A very striking test is the action of adrenalin on the pupil of 

 mammals (rabbit or cats) on the side on which the superior cervical 

 ganglion had been removed 24 hours or longer. If a sufficient 

 dose was used, that pupil showed a maximal dilatation which may 

 last for hours, while the pupil on the normal side remains un- 

 changed. I have studied this test with pituitrin. In six rabbits 



