Now, the inner cell mass, the cells shown in light purple, eventually form these three distinct germ layers, while the cells of the Trophy Blast eventually give rise to the corian as well as to the placenta. And remember, the placenta is a structure that provides a source of nutrition and oxygen from the mother and to that developing organism that developing fetus. Now, let's suppose we move from diagram one to diagram two. 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.