FIGURES 242 AND 243 



242 Same, section 4. 



243 Same, section 10. 



1 Sympathetic nerve. 



2 Intersegmental arteries. 



3 Right azygos vein, thoracic portion. 



4 Atrophying embryonal vein, forming kernel in interior of developing 



and replacing lymphatic space. 



5 Extraintimal or perivenous lymphatic space surrounding degen- 



erating embryonal vein. 



6 Left azygos vein, thoracic portion. 



7 Aorta. 



8 Oesophagus. 



