Fig. 21 Outline of early embryo of Desmognathus before pigmentation, show- 
ing early blood islands. X 10. 
Fig. 22. Early embryo of Desmognathus, showing vessels and channels partly 
extending over the yolk, but with no circulation and no color in the blood. X 10. 
Fig. 23 Early embryo of Desmognathus, the vessels beginning to form appear 
as clear lines on the white yolk. X 10. 
Fig. 24 Side view of another early stage of Desmognathus. X 10. 
Fig. 25 Later stage, Desmognathus fusca embryo, showing early vessels; 
there is yet no color in the blood; the heart is beginning to beat. X 10. 
Fig. 26 Stage in which the lateral cutaneous vessel shows blood colored and a 
complete vitelline circulation. X 12. 
Fig. 27 Later stage of Desmognathus, twisted on the yolk; it shows vitelline 
circulation, lateral cutaneous and the beginning of the first parallel vessel. X 12. 
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