NATURAL SELECTION IN MAN 193 
From the point of view of racial welfare one should distinguish 
between the elimination of infants who are destined to produce 
inferior adults and infants who, though weak, grow up into adults 
who are strong and healthy. The preservation of the latter class 
of infants would not lead to undesirable developments, except 
perhaps in making it necessary for parents to bestow more care 
upon their new born children. As the human species evolved 
from animal ancestry infants became progressively weaker and 
required more and more attention for their successful rearing. 
Along with this there went an increase in the amount of parental 
care devoted to the young. Infants may be very poorly adapted 
to survival in an unfavorable environment and nevertheless form, 
as adults, the most desirable types of the race. Goethe as an 
infant was very puny and his life was for a time almost despaired 
of, but as a man he was exceptionally robust, vigorous and long 
lived. It is only in so far as infantile weakness is correlated 
with weakness or defect in later life that the elimination of the 
less hardy babies would have any relation to racial improvement. 
It is probable that despite many exceptions there is a general 
correlation between weakness in infancy and weakness in later 
life. Ploetz has adduced evidence to show that infant and child 
mortality is less in stocks with greater longevity. Part of the data 
were obtained from records of royal families (fiirstliche Familien) 
of Germany and another part from families mainly of the middle 
class (bargerliche Familien). The results may be seen in the 
following table: 
