70 



Scientific Proceedings (97). 



ical result of intergrowth of tumors and any kind of mesenchymal 

 tissue, for intergrowth takes place between the cells of the Ehrlich 

 sarcoma and mesenchyme of a hatching chick with no injurious 

 effect upon the tumor. The process depends, therefore, upon a 

 property which the mesenchyme acquires after birth. There is a 

 biological functional difference between the embryonic and adult 

 splenic mesenchyme in the chick, apparent in its different response 

 to the living tumor cell of the mouse sarcoma employed in these 

 experiments. The functional capacity of the adult splenic mesen- 

 chyme^ — new in its power to injure a living tumor cell — might in 

 my opinion be induced by factors closely connected with the 

 great changes which take place after birth in all organs of digestion 

 and assimilation. 



40 (1415) 



Further proof of the antagonism existing between the thymus and 



parathyroid. 1 



By Eduard Uhlenhuth. 



[From the Rockefeller Institute for Medical Research, New York City.] 



Larvae of the salamander Ambly stoma opacum when fed on 

 thymus soon after hatching develop tetanic convulsions at an 

 age of from 35 to 40 days. Since at this time the larvae develop, 

 in their own thymus glands, the structures characteristic for the 

 secretory stage of the glands, it was concluded that the amphibian 

 thymus like that of the mammalian thymus excretes a toxic sub- 

 stance producing tetanic convulsions, and that tetany results if 

 the animal's own secretion is added to that introduced by the 

 thymus diet. 



This is confirmed by further experiments (Table I., first four 

 horizontal rows), which show that the interval between the begin- 

 ning of the thymus feeding and the outbreak of tetanic convulsions 

 becomes shorter, the later the thymus feeding is started, while 

 the age at which tetany develops, remains constant. 



If thymus feeding is started after the development of the 

 functional stage of the animal's own thymus glands has taken 



1 Jour. Gen. Physiol., 1918, i., p. 23 and 33. 



