ON THE PRESENCE OF PERMANENT COMMUNI> 

 CATIONS BETWEEN THE LYMPHATIC AND THE 

 VENOUS SYSTEM AT THE LEVEL OF THE RENAL 

 VEINS IN ADULT SOUTH AMERICAN MONKEYS^ 



CHARLES F. SILVESTER 

 Fro7n the Laboratory 0/ Comparative Anatomy, Princeton University 



TWELVE FIGUBES 



The writer has examined eighty-nine adult monkeys, inchiding 

 both Old World and South American species, which have been 

 added to the Princeton Collections during the past two years. 

 In all of these specimens the lymphatic system was injected 

 with colored gelatin solutions, and, in the majority of cases, the 

 injection was made into the inguinal, mesenteric, axillary, and 

 cephalic lymph nodes. 



The following observation was made during the course of this 

 investigation: Whenever the mesenteric or inguinal lymphatic 

 nodes of a New World species were injected the injection mass 

 never passed from the lumbar or intestinal lymphatic trunks into 

 the thoracic duct or into the anterior regions of the body, hut passed 

 directly into the postcava in the region of the renal veins. A more 

 detailed examination of the vessels in this region of the body 

 revealed the fact that the lymphatics of the digestive organs and of 

 the posterior extremities invariably enter the venous system at the 

 level of the renal veins. 



Twenty-five individuals, comprising seven of the twelve gen- 

 era of South American monkeys, form the basis of the present 

 investigation. These posterior communications between the 

 lymphatic and the venous system were found to vary from two 

 to nine in number and were found to open at almost any point 

 on the renal segment of the postcava and its immediate tribu- 

 taries. 



1 Read before the twenty-fifth Session of the Association of American Anato- 

 mists; Boston, Mass., December 28 to 30, 1909, and the II International Ana- 

 tomical Congress; Brussels, August 7 to 11, 1910. 



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