Premature birth ought to be avoided, because the child born too
early is insufficiently equipped for the task before him.
Astengo, dealing with nearly 19,000 cases at the Lariboisière
Hospital in Paris and the Maternité, found, that reckoning from
the date of the last menstruation, there is a direct relation
between the weight of the infant at birth and the length of the
pregnancy. The longer the pregnancy, the finer the child
(Astengo, _Rapport du Poids des Enfants à la Durée de la
Grossesse_, Thèse de Paris, 1905).

The frequency of premature birth is probably as great in England
as in France. Ballantyne states (_Manual of Antenatal Pathology;
The Foetus_, p. 456) that for practical purposes the frequency
of premature labors in maternity hospitals may be put at 20 per
cent., but that if all infants weighing less than 3,000 grammes
are to be regarded as premature, it rises to 41.5 per cent. That
premature birth is increasing in England seems to be indicated by
the fact that during the past twenty-five years there has been a
steady rise in the mortality rate from premature birth. McCleary,
who discusses this point and considers the increase real,
concludes that "it would appear that there has been a diminution
in the quality as well as in the quantity of our output of
babies" (see also a discussion, introduced by Dawson Williams, on
"Physical Deterioration," _British Medical Journal_, Oct. 14,
1905).

It need scarcely be pointed out that not only is immaturity a
cause of deterioration in the infants that survive, but that it
alone serves enormously to decrease the number of infants that
are able to survive. Thus G. Newman states (loc. cit.) that in