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38 
Fig. 38 Section through the ectoderm (e) and mesoderm (m) on the surface of 
the yolk of a Desmognathus embryo, such as is shown in figure 21. The section 
does not pass through a blood island; yolk granules in outline. X 300. 
Fig. 39 Section through a blood island (6) of a Desmognathus embryo, such as 
is shown in figure 21. x 300. 
Fig. 40 Section through a blood channel of Desmognathus before the formation 
of an endothelium; (6), blood cells. > 300. 
Fig. 41 Section through a lacuna (/) on the surface of the yolk of a Desmogna- 
thus embryo. X 300. 
Fig. 42 Section through a blood channel without blood (/) in the dorsal region 
of an embryo of Desmognathus. X 300. 
Fig. 43 Section through a yolk vessel of an embryo about 12 mm. long, showing 
capillary endothelium. X 300. 
Fig. 44 Section through yolk capillary of a 14 mm. embryo of Desmognathus, 
showing endothelium and blood corpuscles (6). X 300. 
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