Frederic T. Lewis 97 
and external jugular veins are merged in an “ anterior cardinal vein,” 
the subeardinals are omitted, the renal and iliac anastomoses are made 
continuous with one another, and: the sciatic and femoral veins are 
reversed. 
Fie. 1. Rabbit, 13 days, 9.5 mm., Harvard Embryological Collection, Series 
498, X 13 diams. 3, 4, and 5 indicate the position of the corresponding 
cervical nerves in this, as in the following figures. The veins shown are 
those of the left side: D. C., duct of Cuvier; Ex. M., external mammary; 
In. J., internal jugular; Pr. Ul., primitive ulnar. 
It was thought that more accurate figures might be obtained by the 
graphic reconstruction of uninjected embryos. The possibility of over- 
looking minute orifices guarded by valves, and the limitation of this 
method to small embryos are obvious disadvantages, but these are offset 
Us 
