And what these digestive, digestive enzymes do is they dig a hole inside the endometrium that can accommodate that implanting embryo. So the embryo slowly begins to make its way into the endometrium of that uterus. Now, implantation takes place on about the 7th day following fertilization. Now, what happens next? Well, by about the 10th day, that entire implanting embryo is found entirely inside the endometrium, as shown in the following diagram. And notice that these cells continue to secrete these digestive enzymes that even further break down this area surrounding that implanting embryo.