embryonic area n.
The area of the blastoderm on either side of, and immediately cephalic to, the primitive streak where the component cell layers have become thickened.
During the fifth day remarkable changes take place in the epiblast of the embryonic area.
The ring around the embryonic area where the walls of the vesicle are formed of epiblast and hypoblast.
Towards the end of the sixth day the embryonic area becomes oval, but the changes which next take place are not understood.
The embryonic area is formed in the usual way, and its long axis is placed at right angles to that of the vesicle.
At the free end of the cylinder there appears on the thirteenth day an embryonic area similar to that of other Mammalia.