ACKNOWLEDGMENT 



We are indebted to the following publishers for permission to 

 use in this book some of the material which has previously ap- 

 peared either in books or magazine articles written by the late 

 Raymond Pearl: W. B. Saunders Company, "Medical Biometry 

 and Statistics/' 1923, 1930 and 1940 editions j Williams and 

 Wilkins Company, "Studies in Human Biology," 1924; Alfred 

 A. Knopf, "Alcohol and Longevity," 1926; Paul B. Hoeber, 

 Inc., "Some Aspects of the Biology of Human Populations," 

 in "Human Biology and Racial Welfare," edited by E. V. 

 Cowdry, 1930; Harper and Brothers, "Patterns for Living 

 Together," in Harper's Magazine, May, 1938; Science Press, 

 "The Search for Longevity," in Scientific Monthly, May, 1 939; 

 Science Press, "Tobacco Smoking and Longevity," in Science, 

 March 4, 1939; Oxford University Press, "The Natural His- 

 tory of Population," 1939; and D. Appleton-Century Com- 

 pany, a reprint of "The Search for Longevity" in "Landmarks 

 in Medicine" (Laity Lectures of the New York Academy of 

 Medicine), 1939. 



