537 



verse sections through the body near the junction of the left sub- 

 clavian and innominate veins where both the venous outgrowth from 

 the left innominate vein (veno-lymphatic anlages of the thoracic duct) 

 and the thoracic duct occupy a position on the medial side of the 

 sympathetic nerve. 



Symph. Thoracic A. thyro- 

 N. duct cerv. 



Symph. 



Anlage 



tlml. (llK t 



L. carot. A. Left com. jug. V. 

 Fig. 3. 



L. r:ii!)t. A. Left com. jug. V. 



Fig. 4. 



Figs. 3 and 4. Microphotographs of transverse sections of a 14 and 16 mm cat 

 embryo, respectively, taken approximately at corresponding levels which are indicated 

 by arrows in Figs. 1 and 2. 



Anlage Symph 

 thor. duct N. 



Verteb. 

 A. 



Thoracic Symph. Verteb. A. thyro- 

 duct. N. A. cerv. 



Innom. A. 



Left innom. V. 

 Fig. 5. 



Subclav. V. 



L. carot. A. Left innom. V. Subclav. V. 



Fig. 6. 



*^. 



Figs. 5 and 6. Microphotographs of transverse sections of a 14 and 16 mm cat 

 embryo, respectively, taken approximately at corresponding levels which are indicated 

 by arrows in Figs. 1 and 2. 



An exact determination of the veno-lymphatic anlages of the 

 thoracic and right lymphatic ducts which arise along the common 

 jugular and innominate veins is coupled with considerable difficulty, 



