72 



Scientific Proceedings (56). 



duct, with contradictory and practically negative results. 1 In 

 cases where we have adequate tests for the internal secretion of an 

 organ (for example, the adrenal glands) it has been shown that 

 these secretions pass directly into the blood, not into the lymph. 

 Despite this, the view that the internal secretions are discharged 

 primarily into the lymph appears to be an attractive one to many 

 physiologists, as shown by the surv ival of this theory in the case 

 of the thyroids, and the recent attempts to secure evidence for 

 the theory in the case of the hypophysis. 



It is not clear that the glycosuria reported by Biedl following 

 interference with the thoracic lymph is true pancreatic diabetes. 

 Ligation of the thoracic duct may cause a temporary hyper- 

 glycosuria owing to injury of the liver by the edema from the back 

 pressure of the lymph. And the fistula experiments do not exclude 

 a temporary glycosuria due to the operation and the anesthesia. 



We have repeated the thoracic duct fistula experiment of 

 Biedl in two dogs with negative results. We found it impossible 

 to maintain a continuous flow of lymph with a cannula in the duct 

 owing to clotting. We therefore ligatured the veins in such a way 

 that the thoracic lymph discharged into the external jugular vein, 

 and this vein was slit open and secured to the skin, thus allowing 

 free escape of the lymph. The dogs were under constant observa- 

 tion throughout the experiment, so that there was no retention of 

 lymph from clotting at the slit in the jugular vein. In Dog I 

 there was free escape of the thoracic lymph for 32 hours, in Dog II 

 for 33 hours. The urine drawn from time to time by catheter 

 showed no sugar at any time. The dogs showed an abnormal 

 thirst, but the total secretion of urine was less than normal, owing 

 probably to the continued loss of lymph. 



Since extirpation of the pancreas brings on diabetes in from 

 6-10 hours, while complete elimination of the thoracic lymph for 

 32-33 hours does not induce even mild glycosuria, it is evident 

 that the internal secretion of the pancreas enters the blood directly 

 and not indirectly via the thoracic duct. 



1 The literature is discussed by Allen, "Glycosuria and Diabetes," Boston, 1913. 



