William Snow ]\[illor 451 



venous trunks by which it is formed. Each Ductus Cuvieri (Fig. 3, 

 D. C.) is formed by the union of the follo\nng veins: 



jugular, 



subclavian, 



posteardinal, 



lateral. 

 The jugular is the largest of the venous trunks and appears as a direct 

 continuation of the Ductus Cuvieri. Its direction is at first dorsal, then 

 curving anteriorly it passes above the subclavian to divide after a short 

 distance into the external and internal jugulars (Fig. 3, Ji.,Je.). Con- 

 nected with the external jugular is a widened expansion, the jugular sinus 

 (Fig.3,Je.). 



The subclavian (Fig. 3, She.) joins the Ductus Cuvieri just internal 

 to the jugular and on its ventral side. The posteardinal and lateral 

 join the Ductus Cuvieri on the caudal side, the lateral being the more 

 external (Fig. 3, "P. C, La.). In some animals these last two veins 

 unite just as they join the Ductus. 



We have seen above hov/ the lymph vessels of the lung are connected 

 with the very rich network of lymph vessels in the walls of the stomach 

 (PL I, Figs. 1, 2, and 3). Arising from the anterior and outer margin of 

 this network of lymph vessels there is found on each side of the stomach a 

 lymph trunk of moderate size which follows the course of the posteardinal 

 vein until just before it joins the Ductus Cuvieri ; it then passes dorsal 

 to the posteardinal and lateral veins and enters sometimes directly into 

 the Ductus Cuvieri, sometimes into the jugular (PL I, Fig. 3). Just 

 before joining the vein this lymph trunk is joined by lymph vessels coming 

 from the head and anterior extremity. 



\ 

 Methods. — The technique of injecting the lymph vessels of the lung of 

 Necturus is quite simple. The animal is killed with chloroform. If, on open- 

 ing the abdomen, the lungs are not well distended, it facilitates the injection 

 to insert a fine glass tube into the glottis and gently fill the lungs with air. 

 The free tip of one of the lungs (I generally make use of the left lung) is 

 grasped with a pair of broad pointed forceps and drawn away from the 

 mid-line; this puts the peritoneal fold on the stretch. A nick is next made in 

 this fold (Fig. 2), close to the artery, with a pair of sharp scissors, care 

 being taken not to wound the artery itself. If the nick has been properly 

 made a probe can now be introduced through this opening into one of the 

 large lymph trunks which runs along the course of the artery. The cannula 

 of a small syringe, which has been filled with a thin vermilion starch mass 

 or Chinese ink rubbed up with normal salt solution, is pushed in beside the 

 probe; the probe is now withdrawn and the cannula held in place between 

 the thumb and finger of the left hand. The piston of the syringe is slowly 



