LIST OF ILLUSTRATIONS 



FACING 

 , PAGE 



Charles Robert Darwin (i 809-1882)^ Frontispiece 



The Chevalier de Lamarck (1744-1829) 18 



Phenacodus, an Early Generalized Mammal 224 



The Dawn Horse 224 



The Three-toed Horse 228 



The American Horse 228 



August Weismann (1834) 238 



Hugo de Vries ..." 246 



