FIGURES 214 TO 217 



214 Transverse section through middle thoracic region in a 14 mm. cat 

 embryo, (series 214, slide XIV, section 15) X 225. 



215 Same, section 16. 



216 Same, section 17. 



217 Same, section 19. 



4 Atrophying embryonal vein, forming kernel in interior of developing 



and replacing lymphatic space. 



5 Extraintimal or perivenous lymphatic space sourrounding degenerat- 



ing embryonal vein. 



