GEISTES AND MANKIND — BLIVEN 301 



family seems to go rapidly downhill from generation to generation, 

 it is only partly because of bad heredity. The rest of the story is 

 environment — poverty, ignorance, and imitation of their elders driv- 

 ing down one crop of children after another. 



Science nowadays looks with deep suspicion on conclusions drawn 

 from the famous "degenerate families" such as the Jukes and the 

 Kallikaks, with which sociologists regaled us a generation ago. No 

 doubt there were some "morbid" genes among the members of 

 these families ; but the sociologists made a bad mistake in attributing 

 the whole evil record to the genes alone and ignoring environmental 

 factors. What chance would even a normal child have had, brought 

 up in a household composed largely of drunkards, thieves, and pros- 

 titutes ? His family record would be enough to turn the community 

 against him from the start. The geneticists of today try to balance 

 the evils transmitted by the genes against those caused by imperfect 

 surroundings. 



4. Alcoholism, as such, probably cannot be transmitted from par- 

 ent to child, though an unstable neural system, predisposing to dip- 

 somania, may be. When the son of a drunkard takes to drink, it is 

 possible that his genes are involved; but it is also possible and even 

 probable, that it is by imitation or in response to a bad environment 

 in which the father's alcoholism played a part. Koughly the same 

 is true of other human weaknesses — drug addiction, sexual promis- 

 cuity, improvidence, love of gambling, habitual lying. 



5. The common belief that the mother's blood circulates through 

 the body of the child before birth is now known to be false. The 

 two blood streams are separated by the placenta, through which 

 nourishment passes by osmosis, which is roughly the way that blot- 

 ting paper picks up moisture. Mr. Justice Holmes in a famous 

 decision once held that an unborn child is "a part of the mother's 

 bowels"; but science has overruled the great Justice. The number 

 of abnormal conditions the mother can transmit to the unborn child 

 is much smaller than is commonly supposed. She can infect her 

 baby with syphilis, but this is not a hereditary form, and responds 

 to treatment. She cannot transmit gonorrhea, although she can 

 infect the child during birth itself. Until a few years ago, thou- 

 sands of children all over the world became blind at birth because 

 of venereal infection transmitted in this way. There are a few 

 drugs which manage to find their way through the placenta, and it 

 is believed, for example, without much reliable evidence, that an 

 unborn child may become a cocaine addict. Certainly the child's 

 genes can be injured before birth by lead poisoning. But such path- 

 ological conditions, at least as between mother and child, are not 

 hereditary and can be treated just as postnatal infections are. 



