X PREFACE TO REVISED EDITION 



chapter from Albert Edward Wiggam's book The Fruit of the Family 

 Tree. The writer has introduced a considerable amount of new matter 

 of his own which consists chiefly of relatively short introductory, con- 

 necting, explanatory, and summarizing statements that serve to 

 cement the otherwise somewhat disconnected excerpts into a coherent 

 whole. Because of the fact that so many of the writer's own contribu- 

 tions are scattered through the book, it is deemed wise to omit his 

 name from all such chapters and passages, with the understanding 

 that all matter not specifically credited to others is his own. 



Excerpts from books commonly contain undefined technical terms 

 that perplex the beginning student. This difficulty has been overcome 

 through the addition of a full glossary defining nearly all of the bio- 

 logical terms used in the book. 



Grateful acknowledgments for the use of new materials are here- 

 with given to the following authors and publishers: E. G. Conklin, 

 R. R. Gates, S. J. Holmes, D. F. Jones, T. H. Morgan, H. F. Muller, 

 G. H. Thayer, A. E. Wiggam, E. B. Wilson; The Bobbs-Merrill Com- 

 pany, Henry Holt and Company, The Macmillan Company, The 

 Princeton University Press, The Williams and Wilkins Company. 



H. H. Newman 

 University of Chicago 

 April 6, 1925 



