PHENOMENA OF INHERITANCE 217 



which n represents the number of generations. 

 There have been about 57 generations since 

 the beginning of the Christian Era, and if this 

 rule held true indefinitely each of us would 

 have had at the time of the birth of Christ a 

 number of ancestors represented by (2)^^ or 

 about 120 quadrillions, — a number far greater 

 than the entire human population of the globe 

 since that time. As a matter of fact, owing to 

 the intermarriage of cousins of various de- 

 grees the actual number of ancestors is much 

 smaller than the theoretical number. For ex- 

 ample, Plate says that the present Emperor 

 of Germany had only 162 ancestors in the 

 10th ascending generation, instead of 512, the 

 theoretical number. Nevertheless this calcu- 

 lation will serve to show how widespread our 

 ancestral lines are, and how nearly related are 

 all people of the same race. 



Davenport concludes that no people of 

 English descent are more distantly related 

 than 30th cousins, while most people are much 

 more closely related than that. If we allow 

 three generations to a century, and calculate 

 that the degree of cousinship is determined by 



