FIGURES 118 AND 119 



118 Same, section 5. 



119 Same, section 6. 



Right precaval vein. 



Atrophying embryonal vein, forming kernel in interior of developing 



and replacing lymphatic space. 



5 Extraintimal or perivenous lymphatic space surrounding degenerat- 

 ing embryonal vein. 

 7 Aorta. 

 9 Trachea. 

 10 Pulmonary artery. 

 22 Vagus. 

 32 Ventral mediastinal venous plexus. 



