 It is the prepared portion of the female’s katamenia that is potentially such as the contributor of semen is actually. And the semen conveys to it a movement or power, such that “when the movement ceases each of the parts comes to be and is ensouled (734b24–25).” That is, in embryological development, each part emerges within a system of parts that is organized to provide nutrition for its growth, and that is guided by a complex ‘program’ for its development. Notice that as each part comes to be it already has the functional capacity associated with it—it comes to be and is ensouled.