PLATK 10 



EXPLANATIOX OF FIGURE 



21 Dniwn from a reconstruction of a chick cnihrvo of (i days and '_M hours, 14 

 mm. (series no. 465). Ventro-mesial view. 



1, aorta ^■^. duct of Cuvier 



2, dorsal aortic roots ^.?, vertebral vein 



3, aortic arch VI 15, jugular lymjih sac 



3n, pulmonary artery 15a, thoracic duct 'approach' of jugular 



5, celiac artery lymph sac 



6, notocord 16, groups of develo))ing blood cells 



10, precardinal vein 17, rudiments of thoracic duct 



11, subclavian vein 



182 



