Mosaic and Regulation Phenomena during the Early Formation of the Chick Blastoderm

Figure 14

Section through heart region of an embryo after 40 hours of culture of an unincubated blastoderm operated on as represented in Figure 13(a). In the unoperated side (left side of the photograph), a normal far extending hemi-pericardial cavity (P) is seen with normal epimyocard (arrowhead). At the operated side, the hemi-pericardial cavity (P) is closed (upwards directed arrowhead) and no blood islands are formed peripherally. S, somite-like material; H, bilaterally formed primary heart tubes. Bar = 100 𝜇m.