FIGURES 164, 165 AND 166 



164 Same, section 25. 



165 Same, section 24. 



166 Same, section 23. . 



1 Sympathetic nerve. 



4 Atrophying embryonal vein, forming kernel in interior of develop- 



ing and replacing lymphatic space. 



5 Extraintimal or perivenous lymphatic space surrounding degen- 



erating embryonal vein. 

 8 Oesophagus. 

 17 Prevertebral venous plexus. 



