March 5, 1915] 



SCIENCE 



345 



sufferers from certain types of blindness 

 and deaf-mutism, there is no direction in 

 which, as yet, general interference would be 

 justified." What is sought in this move- 

 ment is that persons who are such radical 

 defectives through heredity as to be in the 

 nature of public wards should be rendered 

 sterile by as innocuous a means as possible, 

 for, as is well known, such half measures as 

 segregation and the like are too often in- 

 effective. Since society offers a reasonable 

 protection to such individuals, it is, in my 

 opinion, entirely justified in taking this 

 step against those who through irrespon- 

 sibility would inflict upon it additions to 

 its already too lengthy list of defective 

 members. 



But the eugenist is not only concerned 

 with the problem of a humane elimination 

 of the unfit, he is also equally desirous of 

 perpetuating and increasing the most highly 

 gifted in the community. If the best 

 workers and the best thinkers in all lines 

 of modern human endeavor could repro- 

 duce their kind in the next generation to 

 the exclusion of the incompetent and the 

 vicious, civilization would make a stride in 

 less than the span of a single lifetime such 

 as it has never done before. The elimina- 

 tion of the strikingly defective members of 

 society, as I have already tried to show, is a 

 reasonable and a humane possibility. Is it 

 also reasonable to expect that the second 

 part of the eugenics program, namely, the 

 reproduction in future of only the best at 

 hand, is likewise biologically possible 1 



We can approach this question best by 

 asking what constitutes high excellence in 

 any member of the community. Such a 

 member must have the physical qualifica- 

 tions for an ample life during which he 

 must contribute more or less continuously 

 to the welfare of society. He must be phys- 

 ically intact in that he can withstand the 

 wear and tear of daily exertion, and meet 



successfully the strain of momentary 

 crises; and he must cultivate a range of 

 activities that yields products serviceable 

 and acceptable to his community. Modern 

 society has an ample supply of this type 

 of human being and it remains to ascertain 

 the source of his qualities and capacities 

 and the means by which they are handed on 

 to his offspring. The question resolves it- 

 self into one of the nature and amount of 

 human inheritance. 



On this point the facts gathered from 

 animal breeding are most illuminating. 

 Without this source of information, it would 

 have been almost impossible to have formed 

 any adequate idea of the nature of human 

 inheritance. We know full well that the 

 animal breeder has steadily improved his 

 various stocks and that these improvements 

 have become permanent heritable properties 

 of the particular strains with which he has 

 dealt. We also know that the work of the 

 trained breeder is not a haphazard enter- 

 prise, but a well-directed effort in which the 

 constancy of the product can be counted on 

 with ever-increasing certainty. Once well 

 established, a breed will reproduce itself 

 under almost any circumstances with such 

 completeness and fidelity that we scarcely 

 think of the environment as in any way 

 involved and we ascribe the results without 

 further ado to inheritance. To get a Hol- 

 stein cow we invariably draw from Holstein 

 stock; we do not seek to create Holstein 

 surroundings; and experience entirely 

 justifies this procedure. To be sure, we 

 recognize important effects from the envi- 

 ronment. We all know that underfeeding 

 or overfeeding will have an immediate in- 

 fluence upon growth, but we never turn to 

 factors of this kind to change one stock 

 into another. Holsteins are one breed and 

 Guernseys are another, and their immediate 

 characteristics are matters of inheritance, 

 not of environment. 



