FIGURES 132 AND 133 



132 Same, section 16. 



133 Same, section 17. 



3 Right precaval vein, thoracic portion. 



4 Atrophying embryonal vein, forming kernel in interior of developing 



and replacing lymphatic space. 

 6 Extraintimal or perivenous lymphatic space surrounding degenerat- 

 ing embryonal vein. 

 9 Trachea. 

 10 Pulmonary artery. 

 22 Vagus. 



