Before revision: The amniotic cavity is formed by the fusion of the parts of the amniotic fold, which first makes its appearance at the cephalic extremity , and subsequently at the caudal end and sides of the embryo.
After revision: The amniotic cavity is formed by the fusion of the parts of the amniotic fold which first makes its appearance at the cephalic extremity , and subsequently at the caudal end and sides of the embryo.