An Elasto-Plastic Model of Avian Gastrulation #3

This one is quite short but certainly the most important points. Fleury presents:
We assume that the blastodisc is a composite structure, namely a “sandwich”: Extra-Cellular Matrix/ cellular layers/Extra-Cellular Matrix. (p8, c1)
I suppose that here what is described is not the blastodisk but the epiblast. But this is not clear as there are several cellular layers. [...]