FIGURES 167 AND 168 



167 Same, section 43 X 150. 



168 Same, section 44 X 150. 



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. 

 17 Prevertebral venous plexus. 



