What happens in between these two diagrams? Well, basically, the cells of the Trophy Blast begins secreting and releasing digestive enzymes. And these digestive enzymes degenerate this section of the endometrium, and that allows the entire blastocyst to make its way entirely into the endometrium. And that hole is eventually sealed off by blood clots, as well as by developing epithelial cells. So, in diagram two, the entire embryo is found inside that endometrium. And also notice that the cells of the inner cell mass differentiate into two different types of cells.