\viii 1'K'KFACE 



The selected bibliographies which arc appended after 



each chapter constitute tile hest \\orks nil specific poi 

 discussed in tlie course of the chapter. 



Tin- author's indebtedness t<> 1'i-of.-^ >r Kraiiklin II. 

 Giddings for encouragement and stimulating suggestions 

 is greater than can he expressed in a formal preface. 

 lint the author wishes to express his appreciative thanks 

 to Dr. (JiddingS for permission to use unpuhlished 

 material, for reading the manuscript, and for making 

 many criticisms and suggestions which have been of 

 greatest service. 



The author's thanks are also due Professor Leonard 

 S. P>lake\ and Mr. B. .1. Kaldwiu for reading part- of the 

 manuscript and for suggesting the revision of certain 

 details. Acknowledgments and thanks are due the t',,1 

 lowing authors for the courteous permission accorded to 

 copy and reproduce certain diagrams, maps and illustra- 

 tions from their works: Professor F. Birkner, Dei Diln- 



ile Mensch in Europa; Professor Katharine ( '(.man. 

 Tin- I inhibit -'ml History of the Unitrd States; Professor 

 Joseph Dechelette, Manuel D'Archeologie Prehistoriqite; 

 Dr. Robert Forrer, Urgeschichte des Europii* / . Pro- 

 fessor James (Jeikie, The Great Ice Age; Professor M. M. 

 Metcalf, Organic Evolution; Professor AVilliam 'A. Ripley, 

 The Races of Europe; and Professor E. L. Thorndike, 

 Individuality. For extending the same courtesy the au- 

 thor wishes to thank the editors of L'Anthropologi* , The 

 Open Court PuMishinir Company, and the editor, Auguste 

 Picard. 



To the Century Company the author's thanks are due 

 for courtesy in furnishing many excellent illustration- 

 from the Century Ma^a/inc and other of their publica- 

 tions, and for cooperating with the author to secure the 



