312 



The Journal of Heredity 



understood, by selection of the parents 

 good teeth could undoubtedly be in- 

 sured to the next generation. But the 

 question would have to be asked, would 

 it be worth while? The breeder knows 

 how hard it is to fix a number of char- 

 acters at one time, and the student of 

 genetics understands why; and while 

 effort was being concentrated on the 

 teeth other characters wovild run riot. 

 The difficulties are further magnified by 

 the fact, greatly emphasized in recent 

 studies, that the way in which a char- 

 acter will be inherited often cannot be 

 determined by its appearance in the 

 individual. This is a fact which has 

 been almost completely overlooked or 

 ignored in the discussions of socio- 

 logists. So the conservatively inclined 

 need not be alarmed that practical 

 eugenics will do much more than to 

 eliminate the more obviously unfit for 

 some time to come. 



If time permitted I should like to 

 discuss the question of whetlier, in the 

 case of certain specific diseases, such for 

 example as tuberculosis, the greater 

 promise for the race lay in selective 

 heredity, or in environmental adjust- 

 ments, such as prophylactic measures, 

 antitoxins, treatment and the like. My 

 feeling is that in most of these specific 

 cases the race will find it most expedient 

 to do as now, except in such diseases as 

 denote general ])hysical or mental defect 

 or weakness. Take the case of cancer 

 for example. Suppose it were found to 



be definitely inherited, but that medical 

 science could find an easy and early 

 diagnosis and certain cure. Would it 

 not be simpler and easier to cure it as 

 it appeared, even though its incidence 

 should be even larger than now, than to 

 cut ofif all affected lines of germ ])lasm? 

 For certainly the stock that would be 

 eliminated by such measures would be 

 an inestimable loss to the world. 



The very specificity of disease coupled 

 with the difficulty of selecting for a large 

 niimber of characters at once, and 

 taken in connection with man's ]5resent 

 cosmopolitanism, by which all diseases 

 are becoming distributed all over the 

 world within their ]jossiblc ranges — all 

 these factors make the breeding of a race 

 of mankind immune to all, or even to a 

 large number of diseases, a practical 

 impossibility. 



Eugenic selection must, I believe, for 

 a long time be confined as I have said 

 to cases of marked defect and weakness. 

 In addition more study must be given 

 to those influences which may weaken 

 the germ plasm directly, such as alcohol. 

 And medical science, rather than desist- 

 ing, must push on. especially in the 

 field of general prophylaxis, but with 

 more thought to succeeding generations 

 and the future of the race than it has 

 given in the past. Philanthropy and 

 charities cannot stop, but they must take 

 more counsel of established sciences, and 

 like medicine, give more thought to 

 the future. 



Left-Handedness 



As left-handedness is an inherited character, apparently behaving as a Men- 

 delian recessive, it is interesting to note the belief of some investigators that it 

 is one of the stigmata of degeneracy. Bardeleben is quoted in German periodicals 

 as saying; 



"That a few great men, such as Leonardo da Vinci, were left-handed, does 

 not neutralize the prevalent belief — in all ages — that left-handedness imjilics a 

 sub-standard subject. The jjcrcentage of left-handed recruits is Init 6.8; of school 

 children somewhat higher. These figures are very deceptive, however, for of the 

 left-handed children who became right-handed, the percentage is some 26. This, 

 added to the persistently left-handed, raises the original percentage of left-handed 

 considerably." 



After pointing out that the gibbon and orangoutang are as a rule right-handed, 

 and the gorilla and chimpanzee left-handed, the speaker decided there was no 

 evidence at all that a left-handed person was mentally or ijhysically inferior. 



