46 WHAT IS EUGENICS? 



if it seems unlikely that the trouble would reappear in future 

 generations. 



Turning to what is called hereditary feeble-mindedness, 

 what does this mean ? A dose of harmful heredity, if it may 

 be so described, may come into existence in a child, we 

 know not why. This dose may either he quite hidden in that 

 child for all his life, apparently doing him no harm ; or it 

 may make him stupid, ill-tempered, nervous, epileptic, 

 criminal, or with a tendency to drink. In all circum- 

 stances the dose will be passed on to many of the descend- 

 ants of the child in which it first came into existence. Now, 

 if several such doses are passed on to the same child, some 

 coming from one ancestor and some from another, that child 

 will be actually feeble-minded. And something Hke this, 

 only a good deal more comphcated, is how this ailment 

 generally originates ; when it may be called hereditary. 



When such a feeble-minded person marries, some or all of 

 these doses of evil heredity will be passed on to his children. 

 If the child gets as many doses as the parent had, it will be 

 feeble-minded also. If only some of the doses are received 

 by the child, it may show any of the harmful quahties above 

 mentioned. Or a dose may he hidden and unsuspected in 

 the child, though ready to be passed on to its descendants, 

 in whom any of these harmful quahties may, therefore, 

 reappear. 



Somewhere about nine-tenths of all feeble-minded persons 

 probably may be described as suffering from an hereditary 

 disease in this sense. In such cases, some of their descend- 

 ants, if they have any, will be classed as actually feeble- 

 minded, whilst many more will show some marks of 

 inferiority. It follows that, if aU the feeble in mind were 

 to be prevented from having children, much would thus 

 be done to gradually lessen all these evils as the gener- 

 ations succeeded each other. Moreover, no child could 

 then suffer all the harm due to being brought up by a 

 feeble-minded mother. 



If subject to no control, feeble-minded persons would have 

 large famihes and many descendants. This is because they 



