FIGURES 2G0 AND 261 



2G0 Same, section 9. 



261 Transverse section of lower thoracic region in a IG mm. cal fnil)ryo, 

 (series 96, slide XII, section 32) X 200. 



1 Sympathetic nerve. 



2 Intersegmental arteries. 



3 Right azygos vein, thoracic i)orti()n. 



4 Atrophying embryonal vein, forming kernel in interior of developing 



and replacing lyniphatic space. 



5 Extraintimal or perivenous lymphatic space suii-oiiiuliiig degen- 



erating einbrj^onal vein. 



6 Left azygos vcmii. tlioracic portion. 



7 Aorta. 



36 Thoracic (hict. azygos segment. 



