196 THE TREND OF THE RACE 
them because they are unable to do so or because the children 
are unable to take mothers’ milk. ‘These results,” says Pearson, 
“suggest that it is not the artificial feeding, but the health of the 
mother which is the dominating factor in the mortality and 
delicacy of the infant.’ The precise réle of heredity here is, of 
course, not revealed, but the facts indicate that it is more potent 
than the crude data on the relation of artificial feeding to mor- 
tality would indicate. 
Much infantile weakness, however, is the product of purely 
somatic variability, depending upon immaturity of birth, illness 
or misfortune to the mother and many other fortuitous conditions. 
Of the many malformations that cause infants to die soon after 
birth there is in relatively few cases evidence of the hereditary 
character of the defect. Such variability serves to mask more or 
less the true hereditary variations that may be present. Natural 
selection would tend to eliminate the weak or imperfect individ- 
uals whether their defects were hereditary or not, but it is only 
to the extent that the purely hereditary variations are picked out 
that natural selection is able to produce any racial modification. 
A high infant mortality has been considered by some investiga- 
tors as racially advantageous in that a larger proportion of the 
congenitally weak are eliminated. The preservation of a larger 
proportion of the new born would save many weaklings who 
would produce a deterioration of the vitality of the population. 
The Eugenics Section of the American Association for the Study 
and Prevention of Infant Mortality recognized that under present 
conditions the efforts of the society ‘‘must necessarily work some 
anti-eugenic results,” although maintaining, as practically all do, 
that it is an imperative duty to check infant mortality so far as 
possible. No one seriously proposes to do away with medicine 
and hygiene because the death rate in the adult population is to a 
certain degree selective and it would hardly be consistent to deny 
the benefits of medical science to the helpless period of infancy. 
Even those who maintain that a high infant mortality is of racial 
value generally hesitate to advocate the abolition of efforts to 
reduce it. In reading the literature on the subject one cannot fail 
