1. Elizabeth Wyckoff, translator (Chicago: University of Chicago Press, 1954), line 781.

2. David Grene, translator (Chicago: University of Chicago Press, 1942), line 1268.

3. Ovid, Metamorphoses, translation by Frank Justus Miller (Cambridge: Harvard University Press/Loeb Classical Library, 1916, 1976), Book XII, pp. 192–195; Robert Graves, The Greek Myths (Harmondsworth, Middlesex, England: Penguin Books, 1955, 1960), Volume 1, pp. 260–262; Froma Zeitlin, “Configurations of Rape in Greek Myth,” in Sylvana Tomaselli and Roy Porter, editors, Rape: An Historical and Social Enquiry (Oxford and New York: Basil Blackwell, 1986), pp. 133, 134.

4. Smaller amounts of androgens are produced in the cortex of the adrenal gland that surmounts each kidney, from other hormones in the body, and in the placenta.

5. R. M. Rose, I. S. Bernstein, and J. W. Holaday, “Plasma Testosterone, Dominance Rank, and Aggressive Behavior in a Group of Male Rhesus Monkeys,” Nature 231 (1971), pp. 366–368; G. G. Eaton and J. A. Resko, “Plasma Testosterone and Male Dominance in a Japanese Macaque (Macaca fuscata) Troop Compared with Repeated Measures of Testosterone in Laboratory Males,” Hormones and Behavior 5 (1974), pp. 251–259.

6. Peter Marler and William J. Hamilton III, Mechanisms of Animal Behavior (New York: John Wiley & Sons, 1966), p. 177.

7. D. Michael Stoddart, The Scented Ape: The Biology and Culture of Human Odour (Cambridge: Cambridge University Press, 1990), pp. 136, 137, 163.

8. J. Money and A. Ehrhardt, Man and Woman, Boy and Girl: The Differentiation and Dimorphism of Gender Identity from Conception to Maturity (Baltimore: Johns Hopkins University Press, 1972); J. Money and M. Schwartz, “Fetal Androgens in the Early Treated Adrenogenital Syndrome of 46XX Hermaphroditism: Influence on Assertive and Aggressive Types of Behavior,” in Aggressive Behavior 2 (1976), pp. 19–30; J. Money, M. Schwartz, and V. G. Lewis, “Adult Erotosexual Status and Fetal Hormonal Masculinization and Demasculinization,” Psychoneuroendocrinology 9 (1984), pp. 405–414; Sheri A. Berenbaum and Melissa Hines, “Early Androgens Are Related to Childhood Sex-Typed Toy Preferences,” Psychological Science 3 (1992), pp. 203–206.

9. Aristotle, Generation of Animals, in The Oxford Translation of Aristotle, W. D. Ross, translator and editor (London: Oxford University Press, 1928), 737^a28.

10. Stefan Hansen, “Mechanisms Involved in the Control of Punished Responding in Mother Rats,” Hormones and Behavior 24 (1990), pp. 186–197.

11. Mary Midgley, Beast and Man (Ithaca, NY: Cornell University Press, 1978), p. 39.

12. John Sparks with Tony Soper, Parrots: A Natural History (New York: Facts on File, 1990), p. 90.

13. Owen R. Floody, “Hormones and Aggression in Female Mammals,” in Bruce B. Svare, editor, Hormones and Aggressive Behavior (New York: Plenum Press, 1983), pp. 44–46.

14. Alfred M. Dufty, Jr., “Testosterone and Survival: A Cost of Aggressiveness?” Hormones and Behavior 23 (1989), pp. 185–193.

15 Hansen, op. cit.

16. Lester Grinspoon, Harvard Medical School, private communication, 1991.

17. John C. Wingfield and M. Ramenofsky, “Testosterone and Aggressive Behaviour During the Reproductive Cycle of Male Birds,” in R. Gilles and J. Balthazart, editors, Neurobiology (Berlin: Springer-Verlag, 1985), pp. 92–104.

18. Stephen T. Emlen, Cornell University, private communication, 1991.

19. R. L. Sprott, “Fear Communication via Odor in Inbred Mice,” Psychological Reports 25 (1969), pp. 263–268; John F. Eisenberg and Devra G. Kleiman, “Olfactory Communication in Mammals,” in Annual Review of Ecology and Systematics 3 (1972), pp. 1–32.

20. These classic experiments were described by Konrad Lorenz in 1939 and by Nikko Tinbergen in 1948. Some later research suggests that the chicks and goslings become less afraid of a silhouette as they become habituated to it (and it doesn’t eat anyone). Wolfgang Schleidt (“Über die Auslösung der Flucht vor Raubvögeln bei Truthühnern,” Die Naturwissenschaften 48 [1961], pp. 141–142) suggests that birds on the ground are afraid of any unfamiliar flying silhouette, become used to the harmless image of a flying goose, but retain a fear of the less familiar hawk. This is not far from the toddler’s shyness about strangers and fear of “monsters.”

21. Peter Marler, “Communication Signals of Animals: Emotion or Reference?” Address, Centennial Conference, Department of Psychology, Cornell University, July 20, 1991.

22. Marcel Gyger, Stephen J. Karakashian, Alfred M. Dufty, Jr., and Peter Marler, “Alarm Signals in Birds: The Role of Testosterone,” Hormones and Behavior 22 (1988), pp. 305–314.

23. Stoddart, op. cit., pp. 116–119.

24. The chemicals in question are gamma aminobutyric acid and serotonin. Cf., e.g., Jon Franklin, Molecules of the Mind (New York: Laurel/Dell, 1987), pp. 155–157.

23. Heidi H. Swanson and Richard Schuster, “Cooperative Social Coordination and Aggression in Male Laboratory Rats: Effects of Housing and Testosterone,” Hormones and Behavior 21 (1987), pp. 310–330.