G ALTON AND STATISTICAL STUDY OF INHERITANCE 1 67 



parent seeds in size, but to be always more mediocre than they; 

 to be smaller than they if the parents were large ; to be larger 

 than the parents if the parents were very small." He says that 

 this regression is a necessary result of the fact that "the child 

 inherits, partly from his parents, partly from his ancestors. Speak- 

 ing generally, the further his genealogy goes back, the more 

 numerous and varied will his ancestors become, until they cease 

 to differ from any equally numerous sample taken at hap-hazard 

 from the race at large. Their mean stature will then be the same 

 as that of the race ; in other words, it will be mediocre." 



He illustrates this by comparing the results of the combination 

 in the child of the mean stature of the race with the peculiarities 

 of its parents to the result of pouring an uniform proportion of 

 pure water into a vessel of wine. It dilutes the wine to a certain 

 fraction of its original strength, whatever that strength may have 

 been. 



He then goes on to the deduction that the law of regression 

 to the type of the race "tells heavily against the full hereditary 

 transmission of any rare and valuable gift, as only a few of 

 many children would resemble their parents. The more excep- 

 tional the gift, the more exceptional will be the good fortune of a 

 parent who has a son who equals, and still more if he has a son 

 who surpasses him. The law is even-handed; it levies the same 

 heavy succession tax on the transmission of badness as well as 

 goodness. If it discourages the extravagant expectations of gifted 

 parents that their children will inherit all their powers, it no 

 less discountenances the extravagant fears that they will inherit 

 all their weaknesses and diseases. . . . Let it not for a moment 

 be supposed that the figures invalidate the general doctrine that 

 the children of a gifted pair are much more likely to be gifted 

 than the children of a mediocre pair; what it asserts is that the 

 ablest of the children of one gifted pair is not likely to be as 

 gifted as the ablest of all the children of many mediocre pairs." 



In his recent work on " Finger Prints " he says : " It is impossi- 

 ble not to recognize the fact so clearly illustrated by these patterns 

 in the thumbs that natural selection has no monopoly of influence 

 in the construction of genera, but that it could be wholly dis- 

 pensed with, the internal conditions acting by themselves being 



