Mark Twain, in a letter to Annie Sullivan, the teacher of Helen Keller, said:
.....substantially all ideas are second-hand, consciously and unconsciously drawn from a million outside sources, and daily used by the garnerer with a pride and satisfaction born of the superstition that he originated them; whereas there is not a rag of originality about them anywhere except the little discoloration they get from his mental and moral calibre and his temperament, which is revealed in characteristics of phrasing. . . . It takes a thousand men to invent a telegraph, or a steam engine, or a phonograph, or a photograph, or a telephone, or any other Important thing --and the last man gets the credit and we forget the others. He added his little mite --that is all he did.
In 1886 I read Dr. Holmes's poems, in the Sandwich Islands. A year and a half later I stole his dedication, without knowing it, and used it to dedicate mv "Innocents Abroad" with. Ten years afterward I was talking with Dr. Holmes about it. He was not an ignorant ass --no, not he; . . . and so when I said, "I know now where I stole, but who did you steal it from?" he said, "I don't remember;' I only know I stole it from somebody, because I have never originated anything altogether myself, nor met anybody who had.
(Henney, Nella (Braddy), Anne Sullivan Macy, The Story Behind Helen Keller (Garden City, N.Y.: Doubleday, Doran, and Co., 1933), p.162.

I am fully aware that most of the ideas which are expressed here are not original with me. If I could remember where I "stole" them, I would be glad to acknowledge them. In the course of conversations with my colleagues, many of these ideas were probably expressed. With the exception of references to publications, I have been unable to acknowledge this assistance. I can only acknowledge those people who have consciously afforded me a large amount of personal help.
My greatest debt is to my parents for the gifts of life and love, and to my father in particular, for teaching me a gentle skepticism.
My training at the Bronx High School of Science was a wonderful experience, due largely to an enthusiastic faculty. I am particularly indebted to Dr. Charles Tanzer, who enjoyed enthusiastic kids, and encouraged them.
At the University of California at Berkeley, my greatest debts are to Dr. Kenneth B. DeOme, who guided my career as a graduate student with kindness, understanding and almost inexhaustible patience and to Dr. Curt Stern for arousing my enthusiasms for genetics (which led to many other things), and for some very valuable lessons in how to be a teacher.
I received two indispensable kinds of help with this book.One kind was the encouragement that was sorely needed after the completion of the first draft. This was provided by Doctors Ernst Eichwald, Herbert B. Fowler, Louis S. Goodman, Bernard I. Grosser, Thomas C. King, Ralph C. Richards, Maxwell M. Wintrobe, Michael B. Shimkin, Richmond T. Prehn, and Meredith N. Runner; Marilyn and Sherman Jensen, and my daughter Anne E. Pilgrim.
The other kind of help is the criticism that made this a better book. The following people reviewed all or parts of the manuscript: Doctors Earl B. Barnawell, Ralph Meader, Charles W. Mays, Robert W. McDivitt, and Robert Zechnich.
I am indebted to them for their help, but would like to make it clear that the opinions expressed in this book are mine.
The writing of this book was supported in part by Research Career Development Award CA19045 from the National Cancer institute, National Institutes of Health, U.S. Public Service.
I am grateful to Miriam Rich and Earleen Porter for their secretarial assistance.
My "Severest Critic and Best Friend" award goes to Theron Raines.
My greatest debt is to my wife, for almost everything else.