A key issue for commentators on Aristotle’s embryology is the problem of “wind-eggs,” or unfertilized eggs produced by some female birds or fish without male insemination, to which Aristotle assigns some degree of soul in Generation of Animals 2.5. This seemingly contradicts his doctrine that the male provides the form or soul to the new animal being generated whereas the female provides the matter. My dissertation instead argues that when Aristotle’s comments on wind-eggs are placed in the proper context of his account of how egg-laying animals reproduce from GA 3, they do not in fact contradict his doctrine that only the male animal can initiate new life. To do so, I provide the first in-depth reconstruction of his account of oviparous generation, in which I show that Aristotle distinguishes between the production of an egg and the conception of an embryo that develops inside the egg. The dissertation intervenes in the debate about the causal roles Aristotle assigns to the male and female in animal generation, along with raising new philosophical questions about Aristotle’s biology: about the ontological status of eggs, the relationship between foetus and uterus, the application of mereology to living (and pregnant) animals, and his use of the mechanics of gestation in justifying a hierarchy of living beings.