6i8 POPULAR SCIENCE MONTHLY. 



cation with the slow growth of a complicated civilization and an 

 increased demand for horses. 



As inheritance has an influence on the price of horses, what 

 will be the result if we destroy the children of all horses 

 which fetch less than +2 of Galton's scheme, and breed only from 

 that fourth of the whole which sell for more than 75 of his 

 centesimal scale ? 



We may at first get fancy prices for our expensive stock, but if 

 selection cease with this first step, and we supply as many colts as 

 before, while the demand remains unchanged, the price will "re- 

 vert " to the type, and the mean will become the same as it was. 



Does this prove that those qualities in horses for which money 

 is paid have " retrograded to mediocrity " in these descendants of 

 high-priced parents ? It proves nothing of the sort, for the quali- 

 ties which command a price are one thing and the price another. 

 Even if the horses have much more of these qualities than the 

 old stock, the price will still be fixed by the ratio between demand 

 and supply, and while blood will tell in use it will not tell in price. 



It is clear, then, that characteristics of living things which are 

 influenced by inheritance may conform to a type which exhibits 

 "specific stability," "regression to mediocrity," an occasional 

 " sport," and all the other properties of the types which Galton has 

 studied, without furnishing proof that " inherited " qualities be- 

 have in the same way. To prove this we must cancel, or neutral- 

 ize, or make allowance for all the factors which have an influence 

 upon the type, except " inheritance." 



Galton's generalizations upon the laws of inheritance from the 

 statistical study of finger prints rests upon the belief that the pat- 

 terns are inherited. If they are not, they can teach nothing of 

 inheritance. He proves by statistics that they are, to some de- 

 gree, dependent either directly or indirectly upon inheritance, just 

 as the price of horses is, but this is not enough. To warrant his 

 deductions he must prove that inheritance is the controlling factor 

 in determining the type ; that, in the long run, all the other factors 

 will balance ; and this, it seems to me, he fails to prove. He has 

 studied in one hundred and fifty fraternal couples or children of 

 the same parents the frequency with which the same pattern oc- 

 curs on the same digit of both, and he finds that when marked on 

 a scale in which indicates no resemblance and 100 the greatest 

 possible relationship, they show 10 of relationship. This num- 

 ber is great enough to prove the influence of inheritance, but it is 

 too small to show that the patterns are themselves directly in- 

 herited, and it seems to indicate that they are indirectly influenced 

 by some other inherited characteristic, such perhaps as the ratio 

 between the growth in the embryo of the ball of the finger and 

 that of the nail. 



