I am indebted to many individuals for their generous assistance, especially John Davis, M.D. for helpful discussions, and Rea Wilmshurst, C. A. Silber, Burton H. Brody, and Robert Brewer for critical readings of the manuscript. I also thank my editors Robert Wyatt and Iris Bass for their enormous skill and excellent advice, Ida Giragossian for suggesting I give them a try, Annette Johnson and Susan Abramowitz for their selfless efforts on my behalf, and my agent Maia Gregory for her wit and timely encouragement. And, as always, my wife Karen for her unflagging support of everything I have ever done.