most large English urban districts immaturity is the chief cause
of infant mortality, furnishing about 30 per cent. of the infant
deaths; even in London (Islington) Alfred Harris (_British
Medical Journal_, Dec. 14, 1907) finds that it is responsible for
nearly 17 per cent. of the infantile deaths. It is estimated by
Newman that about half of the mothers of infants dying of
immaturity suffer from marked ill-health and poor physique; they
are not, therefore, fitted to be mothers.

Rest during pregnancy is a very powerful agent in preventing
premature birth. Thus Dr. Sarraute-Lourié has compared 1,550
pregnant women at the Asile Michelet who rested before
confinement with 1,550 women confined at the Hôpital Lariboisière
who had enjoyed no such period of rest. She found that the
average duration of pregnancy was at least twenty days shorter in
the latter group (Mme. Sarraute-Lourié, _De l'Influence du Repos
sur la Durée de la Gestation_, Thèse de Paris, 1899).

Leyboff has insisted on the absolute necessity of rest during
pregnancy, as well for the sake of the woman herself as the
burden she carries, and shows the evil results which follow when
rest is neglected. Railway traveling, horse-riding, bicycling,
and sea-voyages are also, Leyboff believes, liable to be
injurious to the course of pregnancy. Leyboff recognizes the
difficulties which procreating women are placed under by present
industrial conditions, and concludes that "it is urgently
necessary to prevent women, by law, from working during the last
three months of pregnancy; that in every district there should be
a maternity fund; that during this enforced rest a woman should
receive the same salary as during work." He adds that the