39^ ON THE NUMBER OF POLAR BODIES, ETC. 



hereditary tendencies. On this fact the well-known differences 

 between the children of the same parents depend. 



But the deeper meaning of this arrangement must doubtless 

 be sought for in the individual variability which is thus con- 

 tinuously kept up and is always being forced into new com- 

 binations. Thus sexual reproduction is to be explained as 

 an arrangement which ensures an ever-varying suppl}'^ of 

 individual differences. 



