368 THE TREND OF THE RACE 
conformation of the pelvis which is correlated, in a measure, 
with other physical defects, the influence of obstetrical skill 
will probably result in saving from elimination the progeny of 
large numbers of imperfectly developed women and thereby 
storing up more troubles for the future. As Dr. Schallmayer 
has remarked, ‘‘The more successfully obstetrics develops, the 
more necessary will it become for future generations.” 
Another much discussed physical defect of modern woman is 
her frequent inability to nurse children. Dr. A. Bluhm who has 
made an exhaustive investigation of the subject estimates that in 
Germany only about two-thirds of the women are able to supply 
their infants with sufficient milk for their needs. Those who have 
lived among primitive peoples have frequently commented on the 
almost universal ability of mothers to feed their children at the 
breast. Dr. Ogata, according to Hegar, states that in Japan 
women nurse their children almost without exception, even in the 
large cities. And among Europeans the women of previous 
generations nursed their children much more frequently than the 
women of the present time. 
While many women are disinclined to nurse their children, 
at least for very long, in these days of artificial substitutes for 
mother’s milk, there is no doubt that a large and increasing pro- 
portion are incapable of discharging the normal function of 
lactation, however much they may desire to do so. It is difficult 
to discover how far the environment of modern woman is respon- 
sible for this change. The fact that the proportion of women 
unable to nurse their children is usually greater in cities than in 
rural districts points to the potency of environmental influences. 
Hereditary defects of lactation would not be eliminated so rapidly 
as under the régime of primitive life, and it is not improbable 
that the diminishing action of natural selection in relation to 
lactation has permitted a certain amount of atrophy of this 
function. 
Inability to nurse children tends to run in families, and, as 
Bunge and others have shown, it is often associated with parental 
alcoholism, tuberculosis and a general neuropathic inheritance. 
