THE FUTURE OF THE HUMAN RACE 23 



would be eminently fitted to become useful members of society, could 

 they be saved. Those who die of bacterial diseases may be unfitted to 

 cope with those diseases, but this does not imply all other forms of 

 unfitness. This has been recognized from time immemorial, in the 

 phrase, " those whom the gods love die young." 



In the second place, it should be pointed out that while much of the 

 elimination now occurring is desirable, it is no doubt preposterously 

 haphazard, and those who so keenly recognize the need for elimination, 

 should be the first to advocate a rational method of bringing it about. 

 This rational method consists, not in the destruction, but in the pre- 

 vention of the unfit. 



At this point it will be useful to leave mankind for a while, and 

 consider some of the recent results of the study of heredity; results 

 obtained mainly from investigations on plants and lower animals. 

 Without going into detail, it may be said that through the researches 

 of Mendel, Bateson, de Vries, Davenport and many others, we have 

 come to a very clear recognition of unit-characters in inheritance. 

 That is to say, particular characters, such as hairiness, eye-color or 

 susceptibility to some disease, are inherited separately, passing from 

 one generation to another much as atoms pass without change from one 

 to another chemical compound. These unit characters may be lost, and 

 sometimes the loss is real and final, sometimes it is illusory, due merely 

 to non-potency. In very simple cases, it is found that the inheritance 

 of these units follows easily recognized laws, the distribution being in 

 accordance with the laws of chance. In others, this is not evident, and 

 in man especially, the results are often perplexing. Thus the mulatto 

 is virtually a blend between the white and black races, and at first sight 

 it is not at all apparent that the racial characters are inherited as 

 separate units. Nevertheless, we have indications of this in the remark- 

 able differences sometimes observed within a single family of mulattoes, 

 and it may well be inferred that further investigation will yield results 

 in accordance with recognizable laws, and in so far predicable in 

 advance. 2 



The absolute distinction which at first seems to exist between char- 

 acters which are inherited as separate units and those which blend may 

 not be real. When the units are obviously separate, but are fairly 

 numerous, they will produce every sort of mosaic, in the most confusing, 

 and at first sight wholly disorderly manner. Let them be somewhat 

 more numerous still and it becomes practically impossible, by mere 

 inspection, to disentangle the result. It is just as black and white balls, 

 if of large size, will appear as separate things when mixed, but if suffi- 

 ciently small will give an apparent blend, of uniform gray. Because 



2 When two " opposing " units coexist after a cross, there not rarely occurs 

 a blended result, due to what is called "imperfect dominance," but this does 

 not prevent complete segregation in a later generation. 



