72 



Scientific Proceedings (97). 



feeding, this being the time required to produce tetany in the 

 larvae, and that the tetany would cease, as in the larva?, about 8 to 

 10 weeks after its commencement. 



Relation Between Tetany in Thymus-fed Larv^ of Amblystoma opacum and 

 the Development of the Larval Thymus-glands. 



Series. 



Age at the Beginning of 

 Thymus Feeding. 



Age at the Beginning 

 of Tetany. 



Time Required to 

 Produce Tetany. 



XVI., 1918 



9 days. 



35 days. 



26 days. 



B.. 1916 



16 " 



39 " 



23 " 



B., 1917 



22 " 



35 " 



13 " 



T., 1917 



26 " 



35-5 " 



9-5 " 



XXV.. 1918 



45 " 



57 " 



12 " 



In order to decide this point, larvae of the salamander A. 

 opacum were fed on a normal diet which was continued for some 

 time after metamorphosis had occurred. Finally three of these 

 animals were put on an exclusive thymus diet. They have been 

 fed now for seven months on a diet consisting only of thymus, 

 but none of the animals has shown any signs of tetany, either of 

 convulsions or paralysis of the muscles, while in the larvae, tetany 

 develops after several weeks of thymus feeding. Two of these 

 animals together with a worm-fed control specimen are shown. 



This finding appears to offer further proof that the ending of 

 the tetany in thymus-fed larvae at the time of metamorphosis 

 is actually due to the development of the parathyroids at that time, 

 and that the parathyroids are capable of antagonizing the tetany 

 toxin contained in the thymus. Consequently tetany resulting 

 from thymus feeding in the salamander larvae is a true parathy- 

 reoiprival tetany. 



41 (1416) 



The behavior of certain digitalis principles in the body. 



By Robert A. Hatcher and Cary Eggleston. 



[From the Laboratory of Pharmacology of Cornell University Medical 

 College, New York.] 



The authors presented an outline of their method of estimating 

 the absorption, destruction and elimination of several of the 

 digitalis principles in the rat, and that of ouabain in the cat, with 

 the results of some of their experiments. 



