530 EVOLUTION, GENETICS, AND EUGENICS 



three other children one was insane and two weak. The children of 

 Charles EX were both remarkably able. The daughter Catherine 

 becomes the mother of a later succession of kings. Her son Charles X 

 and his son Charles XI were rather mediocre; but Charles XI, with 

 this fine stock behind him, married Ulrica Eleanor (7), granddaughter 

 of Christian IV of Denmark, the most brilliant of all Danish sovereigns, 

 and Charles XII, their son, is pronounced by Voltaire the most 

 remarkable man who ever existed. Charles XII had no children: 

 the succession passed to his sister's son, Adolph Frederick of Holstein- 

 Gottorp, who married Louisa Ulrica, sister of Frederick the Great 

 of Prussia. ^ The result of this union of two great lines of hereditary 

 abihty was Gustavus III, a fit successor of Gustavus Vasa, Gustavus 

 Adolphus, and Charles XII; he was " a prodigy of talents," statesman, 

 poet, dramatist. 



