THE STUDY OF INHERITANCE. 481 



iar word is chosen witli so much, aptness that it does its duty and 

 presents the new conception better than a compound from two or 

 three dead languages. The terms " mid-parent " or " mid," " fra- 

 ternity," " nurture," and " Q " can not mislead or convey any idea 

 except the right one. 



The reviewer's debt to Galton is very great, and it is acknowl- 

 edged with gratitude. Such acquaintance with the statistical 

 method as he possesses he owes to the study of these books ; espe- 

 cially the ones on Hereditary Genius (1869), on Natural . Inherit- 

 ance (1889), and on Finger Prints (1893). 



The attempt to question Galton's generalizations may there- 

 fore seem ungracious and presumptuous, but the uncertainties of 

 vital statistics are proverbial ; and it is not impossible that Gal- 

 ton's data may fail to cover all the ground needed to prove his 

 general conclusions. 



One of these generalizations is so far-reaching that, if it is 

 well founded, it must lead to profound and fundamental changes 

 in our view of the origin of species. 



According to Darwin and Wallace, specific identity in living 

 things is the outcome of the extermination, in the struggle for 

 existence, of the individuals which depart too widely from that 

 "type" which is on the whole best adapted to existing conditions. 

 As these conditions change, the "type" is also slowly modified 

 through a change in the character of this process of extermina- 

 tion. According to this view, the " type " is the outcome of the 

 statistical " law of error," or the deviation from the mean, which 

 holds good in the environment ; and while the " events " are prop- 

 erties of the organism, the type is fixed by the external world, 

 and not by anything in the organism itself. 



Galton holds that specific identity is not due to the process of 

 extermination, but to " organic stability." As I understand him, 

 he holds that this fills up the gaps made by extermination, and 

 thus keeps the type intact. 



This "principle of stability," which is held to result in the 

 permanency of tj^pes, is said to be quite independent of selection. 

 " Genera and species may be formed without the slightest aid 

 from either natural or sexual selection." " Organic stability is 

 the primary factor by which the distinctions between genera are 

 maintained." 



Galton holds, furthermore, not only that specific stability is 

 independent of selection, but that selection is " scarcely compe- 

 tent" to effect a change of type " by favoring mere varieties " 

 that is, by the extermination of the ordinary slight differences be- 

 tween individuals; and that it is only when a "sport" has made 

 its appearance, only when the type has actually changed, that 

 selection can exert any influence. According to this view, the 

 VOL, xLviii. 34 



