JORDAN XIII 



PLATE 4 



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1. Transverse section of same 5-day embryo at a level 300 microns forward 



of section fig. 2, plate 3, through the cord of segregated germ-cells (A) 

 at left. The cord has made a linear connection with the overlying 

 visceral mesoderm and the germ-cells are migrating into it and mov- 

 ing medially. Photo, x 100. 



2. Section through abdominal aorta and adjacent masses of sympathetic 



neuroblasts, 150 microns behind section fig. 3, plate 6. The arrows point 

 to the primordial germ-cells among the neuroblasts. (A) aorta filled 

 with blood dorsally ; (h), hemoblasts separating from endothelium vent- 

 rally. Photo, x 400. (Helly fixation; iron-hematoxylin stain.) 



