Introduction; Aristotle's philosophy and the Generation of Animals Andrea Falcon and David Lefebvre; Part I. The Unity and Structure of Aristotle's Generation of Animals: 1. 'One long argument?' The unity of Aristotle's Generation of Animals Allan Gotthelf and Andrea Falcon; 2. Parts and generation: the prologue to the Generation of Animals and the structure of the treatise David Lefebvre; 3. Order and method in Aristotle's Generation of Animals 2 Mariska Leunissen; Part II. The Principles of Animal Generation Reconsidered: 4. What is Aristotle's Generation of Animals about? Pierre Pellegrin; 5. Aristotle on epigenesis: two senses of epigenesis Devin Henry; 6. A latent difficulty in Aristotle's theory of semen: the homogeneous nature of semen and the role of the frothy bubble Marwan Rashed; 7. Function and instrument: toward a new criterion of the scale of being in Aristotle's Generation of Animals Cristina Cerami; Part III. Hybrids, Male and Female, Particular Forms, and Monsters: 8. Hybridity and sterility in Aristotle's Generation of Animals Jocelyn Groisard; 9. Females in Aristotle's embryology Jessica Gelber; 10. Something(s) in the way(s) he moves: reconsidering the embryological argument for particular forms in Aristotle Gregory Salmieri; 11. Aristotle's explanations of monstrous births and deformities in Generation of Animals 4.4 Sophia Connell; Part IV. Methodology in Aristotle's Generation of Animals: 12. The search for principles in Aristotle: Posterior Analytics 2 and Generation of Animals 1 Robert Bolton; 13. Aristotle, dissection, and generation: experience, expertise and the practices of knowing James G. Lennox.