Acknowledgements
Th e observations of man y peopl e, only some of whom are quoted , made this book
possible. I would like to extend my thanks to all who have contrib uted to the se
subjects and onl y wish th at it would have been po ssible to acknow ledge th e work
of all.
The latter part of th is book was writt en whil e I was a guest of the Commissariat
aL'Energie Atomique. I would like to th ank th em for their ho spitality, particularl y
Profes seur J. Coursaget, Chef du Departernent de Biolo gie, and Dr. Jean Maerz
and his Groupe de Biolo gie. The help and guidance of Jean Maetz made the latter
part of this book possible. Dr. Erik Skadhauge kindly gave me some advice on
avian matters.
The Mount Sinai School of Medicine of the Cit y Universit y of New York
kindl y granted me leave so that I could join the Commissariat aL'Energie Atomique. A number of nice ladies have helped me during the various stages in preparation of this manuscript ; special thanks are due to Mr s. Jean Homola, Mr s.
Norma Beasley, Miss Mar guerite Murphy and Mrs. Wolina Shapiro.
My wife showed consider able forbearance and gave much needed help in the final
preparation of the proofs. Th e editorial help and advice of Dr. D . S. Farner is gratefully acknowled ged as well as the cooperation of the staff of Sprin ger -Verlag in
Heidelberg and Mr. B. Grossmann in New York.