 Another issue that Aristotle treated extensively with relevance to the conception of species—embryogenesis—also had important implications for later discussions. In the traditions indebted in some way to Aristotle’s natural philosophy, sexual generation and the subsequent embryological development of the individual from primordial matter, is a sequential process that occurs in time under the teleological action of the soul (psuche). In Aristotle’s own account, this soul-as-form is typically derived from the male parent, but it could also be derived even from the sun, as employed in his explanation of the origin of spontaneously-generated forms (Aristotle, De generatione animalium, III: 762a, 20–35).