DISTRIBUTION OF LYMPHATICS IN SCORIVENICHTHYS 75 



stem emptying into the ventral pericardial sinus between the 2 

 pharynx vessels. It apparently arises solely from the thyroid 

 gland, and it may have some direct connection with some of the 

 branches of the inferior jugular that run along the dorsal sur- 

 face of the gland. 



During the early stages of this work I had no inference that 

 either the pharynx or the thyroid lymphatic vessels had any 

 communication with the inferior jugular. Later on a specimen 

 was dissected in which the entire venous system, with the single 

 exception of the jugular and its branches, was found to be well 

 filled from an injection of the myelonal lymphatic trunk. This 

 of course led me to believe that there must be another commu- 

 nication with the venous system in the head region other than 

 the cephalic sinus, and most careful search was made of all the 

 lymphatic vessels surrounding the jugular, precava, sinus 

 venosus, and especially lobe (b) of the pericardial sinus ; still 

 no connection whatever was found. Also every opening into 

 these veins was accounted for. As the work progressed the 

 lymphatics of several heads was injected from the ventral 

 lymphatic trunk, and as a rule in these specimens the pericar- 

 dial lymphatic sinuses, the thyroid, and pharynx lymphatic ves- 

 sels were well filled, and the mass entered the nutrient branchial 

 and the inferior jugular veins, but rarely extended in the inferior 

 jugular as far back as the sinus venosus ; it would first run out 

 some of the cut lymphatic vessels that were severed in removing 

 the head. In one specimen I first injected the venous system 

 from one of the hepatic veins with a blue mass, and after allow- 

 ing the mass to partially solidify, injected the lymphatics with a 

 yellow mass from the ventral lymphatic trunk. The lymphatic 

 sinuses, pharynx, and thyroid lymphatic vessels were found to 

 be well filled with the yellow mass, as was also the nutrient 

 branchial veins, and the yellow mass had forced back the blue 

 a short distance in the inferior jugular vein. Upon further dis- 

 section the entire venous system, including the jugular and the 

 dorsal nutrient branchial veins, was found to be filled with the 

 blue mass, indicating of course that a connection must exist be- 

 tween either the pharynx or the thyroid lymphatic vessel and one 

 of the branches of the inferior jugular. By dissection I have 



