THE WORLD’S DEBT TO THE IRISH 
ity may develop unless there is a definite taboo set 
up. Studies in heredity in recent years have shown 
however that there is an excellent physical reason 
for prohibiting the marriage of near relatives since 
such marriages are much more frequently followed 
by inherited defects of various kinds. For the cen- 
sus of 1910 Mr. Alexander Graham Bell provided 
the funds for a special study of the inheritance of 
blindness and deafness and the statistics showed 
that blind and deaf children occurred some four 
times as frequently in the families of parents who 
were near relatives than in those who were not 
related. The Irish observance of the Church laws 
prevented the occurrence of this abuse under cir- 
cumstances such that it might readily occur. As a 
result the health and strength and normality of the 
population in both body and mind was well above 
the average of the peoples around them. 
The Irish custom of having a number of children 
in the family also provided a better outlook for the 
race not alone in numbers but also in vigor of mind 
and body. It has come to be recognized now that 
a considerable amount of the tendency to be strong 
and healthy in both mind and body is born with the 
child and is dependent to no slight extent on its con- 
dition at birth. The successive children in the fam- 
ily up to the sixth or seventh are each on the average 
half a pound heavier and probably have a better 
chance for normal mental and physical development. 
The best mentalities in the family come as a rule 
after the fourth or fifth. The large families of the 
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