We have progesterone, shown in blue. We have the luteinizing hormone in red. And we have the follicle stimulating hormone in purple. And finally, this describes the development of that follicle, the rupture of the follicle, the release of the secondary oxide and the formation of the corpus luteum and the eventual deterioration of the corpus luteum into the corpus albicans assuming no fertilization actually took place. So in this lecture we're going to assume that no fertilization actually takes place. So let's begin at the beginning what happens during the follicular phase.