THE BREEDING OF MEN 



that there is no necessary danger in such unions 

 provided there is no defective strain in the family. 



On the contrary, a desirable quality, even 

 genius itself, may be thus accentuated, as we saw 

 illustrated in the case of the family of the seven 

 brothers. 



If, however, a defective strain exists, the mar- 

 riage of cousins brings together the two defective 

 elements in precisely the way best suited to make 

 them tangible in the offspring. 



The practical lesson is that if there is a strain 

 of mental defect or of susceptibility to tubercu- 

 losis to name only two important conditions 

 in your family, it would be unwise for you to 

 marry a cousin, although such a union might 

 otherwise be not undesirable. The same objection 

 applies to the union of individuals who have the 

 same defect. 



Thus it appears that the new knowledge of 

 heredity does not necessarily tell whom you should 

 marry, but may tell whom you should not marry. 

 It is believed that a knowledge of Mendelian 

 heredity will serve as a guide to intelligent cou- 

 ples in future, and that the happiness of the in- 

 dividual and the welfare of the race will thereby 

 be vastly enhanced. 



A fuller treatment of this aspect of the subject 

 will of course be given in a later chapter. 



[261] 



