embryonic structure epiblast (generic) http://upload.wikimedia.org/wikipedia/commons/e/e3/Gray21.png MP says - tissue that gives rise to the ectoderm, endoderm and mesoderm of the embryo proper. In HOG, epiblast is part of primitive streak/blastpore, which is inconsistent with the MP definition of primitive streak as a ridge of the epiblast. Note that these terms, epiblast and hypoblast, are also used to describe layers of the avian embryonic blastoderm, but the layers so-named seem to be altogether different in these two kinds of vertebrate embryos(CVS). Consider obsoleting this as a grouping class