ACCUMULATION OF DIFFERENCES. 95 



We have no statistics of cattle or horses, 

 but it is well known that many exceptionally 

 fine animals left no immediate descendants 

 equally good, and it is well established that 

 there were as fine cattle and horses ten gen- 

 erations back as there are to-day ; proving \ 

 perhaps as fully as such questions can be 

 proved, that the accumulation of beneficial 

 differences is strictly limited. 



Development cannot, as we have said, 

 exceed a full expression of the life-force of 

 the race. 



Galton seems to have been struck by the 

 rapid extinction of the peerages gained by 

 eminent lawyers, and thinks it was because 

 the peers married heiresses as it appears 

 from their family histories the most of them 

 did. The mere possession of fortune could 

 not affect fertility, but it may be inferred 

 that a great heiress was the last of a high- 

 bred family, or the daughter of a man of pre- 

 eminent ability in some direction, and that 

 high breeding, or the pre-eminence of the 

 father or of the judge himself, not the for- 

 tune, was the reason why the peerage be- 

 came extinct. 



The statistics collected by Galton go to 

 prove that there is a cycle of development 

 retrogression, that the development above 



