76 DEVELOPMENT OF THE SYSTEMIC LYMPHATIC VESSELS 



In the other type, illustrated by series 142 (figs. 83 to 88; fig. 

 91) the thoracic duct approach, maintaining the identical relation 

 to left superior intercostal and common jugular veins, gains the 

 ventro-medial aspect of the sympathetic cord, by passing ob- 

 liquely between the same and the vagus. 



In schematic cross section these two conditions may be illus- 

 trated by the accompanying text figures: 



In regard to the remaining structures fig. 87 (series 142, slide 

 X, section 22) shows, by comparison with the preceding figure 

 86, the tap of the jugular approach into the internal jugular vein 

 (25} just above the confluence with the jugulo-cephalic trunk 

 (29], and the prolongation of its ventral process (13) over the 

 ventral aspect of the common jugular angle. Fig. 88 (series 142, 

 slide X, section 24) shows the confluence of the internal jugular 

 (25) and jugulo-cephalic (29) veins fully established, and gives 

 a very clear picture of the relation which the ventral prolongation 

 (13) from the jugular approach of the lymph sac bears to the 

 common jugular angle. In both figs. 87 and 88 the dorsal venous 

 tributary (sup. intercostal vein anlage) is indicated by the 

 leader 16. It enters the main vein in section 3 of the following 

 slide (xi). Fig. 91 gives the dorsal view of the reconstruction 

 of the vascular and nervous structures of the left side in slides 



