before embarking on my magnum opus about macroevolution. And I'm mighty glad I did because, in the meantime, my views on macroevolution have changed drastically and my original plan, had it been executed, would now be an embarrassment to me.

In addition, I wish to thank Tony Hallam for providing me office space in the very area of the Oxford Museum where Huxley debated Wilberforce; Gary Freeman for sharpening my perception of the essential differences between von Baer and Haeckel during a protracted argument; J. B. S. Haldane (posthumously) for being so brilliant and inserting major insights into the most conventional research reports; Jim Mosimann for taking time (as busy scientists so rarely do) to write a long letter explaining his views on the independent measurement of size and shape; Gary Sprules for his extra effort in responding to an annoyingly time-consuming inquiry about amphibian neoteny; Mary-Claire King and Allan C. Wilson for publishing their important paper on chimp-human differences just when I was floundering for want of an epilogue; Roy Britten and Eric Davidson for a rather inebriated argument about regulation (which I remember though they may not) at Jim Valentine's house; Jane Oppenheimer for serving as a preeminent model of an excellent scientist who can be an equally excellent historian and for reading with so much insight and at such short notice the historical chapters of this book; G. Ledyard Stebbins for his irrepressible enthusiasm about all things and for convincing me about "increasing precocity of gene action" at a crucial time; John Bonner for his quiet and eloquent campaign to unite the two biologies on their common field of development; Frank Sulloway and Robert McCormick for helping me through a terra incognita of Freudian studies; E. O. Wilson for the richness, order, and clarity of his thoughts and for access to his magnificent reprint collection on locusts; Michel Delsol for making this a transoceanic venture by sharing the concerns of French scientists and for his generosity in sending me the manuscript of his unpublished book on the same subject; Agnes Pilot (may everyone have such an intelligent and conscientious German-speaking secretary when 80 percent of the research is auf Deutsch); Saul Steinberg for permitting me to exploit his work in a frontispiece; Bill Coleman and Camille Limoges for their historical insights and ready references; Gordon Cantor for his extremely kind and unsolicited effort to guide me through literature on child development; Robert Fagen, Richard Estes, and Valerius Geist for their thoughts on neoteny in social mammals; Doug Gill for the same in amphibians; Tim Smock for his goodwill in wading through a dull literature on primary education. All these were acts of kindness for no personal reward; this is the true spirit of collegiality. Also, my thanks