34 HEREDITY AND SOCIETY 



alcoholic excess. Those specially susceptible to the 

 charms of alcohol tend to die younger than those able 

 to resist. In natural conditions, therefore, they tend to 

 leave fewer children, and the race gradually contains 

 fewer and fewer individuals liable to alcoholism. In 

 classical times, the Mediterranean races were compara- 

 tively drunken. Now, after centuries of easy access to 

 alcohol, they are very sober. Were they denied access 

 to alcohol, they would tend to revert once more to a 

 renewed liability to drink. The same process of the 

 slow elimination of alcoholic strains has been at work 

 in Northern races. Selection, aided doubtless by the 

 efforts of the advocates of temperance, is making them 

 more sober. But, as in so many other cases, it is 

 possible that the process of selection has now been 

 affected by the voluntary limitation of the birth-rate of 

 the last forty years. The sober and cautious may now 

 have fewer children than the reckless and drunken, 

 and the race may tend to revert to a greater love for 

 alcohol. 



Even with diseases that are commonly accepted as 

 infectious, such as tuberculosis, these considerations 

 should not be overlooked. Of late years so much 

 stress has been laid on the prevention of tubercular 

 infection that we are apt to forget that, while the 

 disease is definitely microbic and infective, the tendency 

 to the disease is as definitely hereditary. For instance, 

 there is evidence to show that there is less transmission 

 between husbands and wives than between parents and 

 children or brothers and sisters, where contiguity is 

 complicated with consanguinity. 



But, since a tuberculous tendency is hereditary, and 



