FIGURES 126 AND 127 



126 Same, section 7. 



127 Same, section 8. 



3 Right precaval vein. 



4 Atrophying embryonal vein, forming kernel in interior of developing 



and replacing lymphatic space. 



o Extraintimal or perivenous lymphatic space surrounding degenerat- 

 ing embryonal vein. 

 7 Aorta. 

 9 Trachea. 

 10 Pulmonary artery. 

 22 Vagus. 

 32 Ventral mediastinal venous plexus. 



