Value of Sexual Reproduction. 159 



Two parents means four grandparents ; and as 

 each grandparent had in turn two parents, that 

 implies eight great-grandparents ; and, having gone 

 back twenty generations we are confronted by the 

 creditable number of one million forty-eight thou- 

 sand five hundred and seventy -six ancestors ! 



Think of that ! In twenty generations each de- 

 scendant from two parents has had over a million 

 ancestors from whom to inherit power ! 



Certainly there need be no lack of variety here. 



One ceases to wonder how certain individuals, 

 unlike the rest of the family, have come by their 

 characteristics. 



Somewhere among that long line of ancestors 

 a long forgotten one has been revived in this 

 stranger in the family. 



Marvellous beyond telling is this power of inher- 

 itance. On the tiny egg-cell, and \-et more tiny 

 sperm-cell have been ineffaceably stamped the 

 characteristics of countless ancestors, — these char- 

 acteristics some day to be unexpectedly revived in 

 a remote descendant. 



This wonderful power to vary, which in the 

 higher life seems to be intimately connected with 

 the power to live, gets its greatest impetus from 

 sexual reproduction. 



Thus is the production of the higher life from 

 the union of two not only necessary, but the great- 

 est of all nature's achievements, insuring boundless 

 vitality and infinite variety. 



