ay- 



Fig. 3 Rabbit . s', days, 6 to .7 segments, 3.4 mm., H. E.< ). no. 62 1. Reconstruction of t he 

 angioblast of the right side, anterior third of the embryo, dorsal view. ( hientation as in fig. 1. 

 The coelom is represented as opened to show the lateral heart within. Au.il. = network to 

 form the dorsal aorta; Ar.l = first aortic arch; Con. Art. = conus arteriosus; l"e.=venous end 

 of lateral heart, with vitelline vein entering it. x-ij indicates plane of section of fig. 4. 

 Broken line marks limit of medullary groove. X 200. 



118 



