FIGURES UO AXD 141 



140 Same, section 24. 



141 Same, section 25. 



3 Right precaval vein. 



4 Atrophying embryonal vein, forming kernel in interior of developing 



and replacing h'lnphatic space. 



5 Extraintimal or perivenous lymphatic space surrounding degen- 



erating embryonal vein. 



6 Precardinal or precava of left side. 



7 Aorta. 



S Oesophagus. 



9 Trachea. 



10 Pulmonary artery. 



22 Vagus. 



