cit.) that in 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.