THE STUDY OF INHERITANCE. 625 



"We must not forget, in addition, that, in a state of Nature, se- 

 lection is neither for one feature, nor is it pedigree selection, or 

 breeding from the fittest. 



It is the extermination of the unfit, and unfitness may come 

 from the imperfect co-ordination of the whole, or from defect in 

 any quality whatever. 



It is undoubtedly true that many of our domesticated races 

 can be proved to have arisen as " sports," and that no great change 

 of type can be effected, hy the methods of the breeder, without 

 sports ; but there seem to be both evidence and theoretical ground 

 for holding that, in this particular, artificial selection furnishes 

 no measure of natural selection. 



It seems to me that, notwithstanding the great value of Gal- 

 ton's data, they fail to prove that the " principle of organic sta- 

 bility " owes its existence to anything except past selection; that 

 regression to mediocrity occurs when ancestry is studied uncom- 

 plicated hj nurture J that the "mid-parent" is anything else than 

 the actual parent; that "sports" are fundamentally different 

 from the ordinary differences between individuals ; or that nat- 

 ural selection is restricted to the preservation of sports. 



Our tendency to believe that a type is something more real 

 and substantial than the transitory phenomena which exhibit it 

 is deeply rooted in our minds. 



As the very nature of this belief renders disproof of it impos- 

 sible, we can feel little surprise at its appearance and reappearance 

 time after time in the history of thought, although science is 

 based upon the well-warranted opinion that, whether types are 

 real or unreal, we know them only as generalizations or abstrac- 

 tions constructed by our minds out of our experience of the 

 orderly sequence of phenomena. 



In zoology and botany the conception of species is unquestion- 

 ably valid and justifiable, and as its most obvious characteristic 

 is its "persistency, as contrasted with the fleeting procession of 

 evanescent individuals, we can not wonder at the vitality of the 

 belief that specific types of life are more real than the individual 

 animals, although Darwin's work has done away with whatever 

 evidence may at one time have seemed to support this belief. 



To the further question, whether specific types are inherent 

 in living matter or external and objective to it, Darwin answers 

 that they are both ; that they are inherent, insomuch as all their 

 data, or " events," are properties of the physical basis of life ; 

 but that they are external, inasmuch as the agreement of the 

 " events " with the " law of frequency of error " is the effect of 

 the environment. 



Biology is not a closed science, and Darwin's view of the 

 matter is not proved ; possibly it is not provable ; but its great 



