PLATE 6 



EXPLANATION OF FIGURE 



7 Reconstruction of a 20 mm. Tragulus embryo. Collection No. 202. X 100. 

 Showing the axial veins and lymphatics. 6, umbilical vein; 17, pre-cava; 18, 

 hepatic portion of post-cava; 19, sub-hepatic portion of post-cava; 20, post- 

 cardino-cardinal collateral anastomosis ; 21 , cardinal collateral vein ; 22, confluence 

 of iliac veins; 23, arch of aorta; 24, aorta; 25, jugula lymph sac; 26, dorso-lateral 

 process of the lymph sac; 26a, dorsal descending process of the lymph sac (tho- 

 racic duct approach) ; 26b, ventral descending process of the lymph sac (broncho- 

 mediastinal approach); 28. azygos segment of thoracic duct; 29, post-azygos 

 segment of thoracic duct; 30, cephalic division of pre-azygos segment of thoracic 

 duct; 31, caudal division of pre-azygos segment of thoracic duct; 32, sympathetic 

 nerve; 33, vagus nerve; 34, ureter; 35, jugular vein; 51, azygos vein; 62, dorsal 

 segmental vein; 68, pancreas. 



232 



