PLATE 3 



EXPLANATION OF FIGURES 



3 Grosser embryo, slide 3, row 3. Junction of bo(ly-stall< and yolk-sac, and 

 connection of the two vascular nets, along the side of the allantois, between the 

 mesoderm and entoderm. All., cavity of allantois, looking into yolk-sac; Am., 

 cavity of amnion, which at one point is fused with the allantois; Ent., sheet of 

 entoderm forming wall of yolk-sac and continued as aUantois wall; Ales., sheet of 

 mesothelium continued from yolk-sac to body-stalk; Vs., cavitj' of yolk-sac. 

 X 400. 



470 



