And what those digestive enzymes do is they begin to break down and digest the vascular and connective tissue found inside that endometrium. And that not only allows the embryo to make its way entirely into the endometrium, but it also forms these tiny extensions, tiny projections known as the Corianic villi. So the purple section is the Coriane that develops from the Trophy blast of that blastocyst that implants itself onto the endometrium. And these Corianic extensions are known as Coryonic villi, and they basically form a structure that looks like a capillary bed. So as the circulatory system, as the cardiovascular system of that growing embryo develops, these Corianic extensions begin to become populated with the blood vessels. And so inside these Corianic villi, if we take a cross section, we'll see this population of blood vessels.