And these are the purple cells, the dark purple cells found as shown. We have the light purple cells that form the inner cell mass. And this entire inner cavity that contains a fluid that provides nutrition to these developing cells is known as the blastocean. 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.