PLATE o 



EXPLANATION OF FIGURES 



6 Grosser embryo, slide 3, row 5, sect. 3. From the edge of the body-stalk, 

 to show surface mesothelium (Mes.) and mesothelial cord, leading from funnel (/.) 

 to unlined space (a). Coe., coelom; b, smaller unlined space; c, endothelial cord. 

 X circa 580. 



7 Grosser embryo, slide 3, row 4, sect. 5. From the edge of the body-stalk, 

 to show mesothelial cord leading to unlined space, containing corpuscles, c and 

 d, mesothelial cords (see text) ; Coe., coelom. X circa 800. 



9 Alinot embryo, H.E.C. no. 825, sect. 25. Vessel from the body-stalk, to 

 show delamination of endothelium, and its extension as cords. Further descrip- 

 tion in text. Coe., coelom; bl.v., blood-vessel. X circa 800. 



10 Minot embryo H.E.C. no. 825, sect. 24. Angioblast net in the chorion, 

 to show the irregular contour of the cord, suggesting amoeboid movements, and 

 the extra-intimal space even around the young branch. X circa 540. 



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