Such a tendency to premature birth under the exciting nervous
influences of civilization would thus correspond, as Bouchacourt
has pointed out (_La Grossesse_, p. 113), to the similar effect
of domestication in animals. The robust countrywoman becomes
transformed into the more graceful, but also more fragile, town
woman who needs a degree of care and hygiene which the
countrywoman with her more resistant nervous system can to some
extent dispense with, although even she, as we see, suffers in
the person of her child, and probably in her own person, from the
effects of work during pregnancy. The serious nature of this
civilized tendency to premature birth--of which lack of rest in
pregnancy is, however, only one of several important causes--is
shown by the fact that Séropian (_Fréquence Comparée des Causes
de l'Accouchement Prémature_, Thèse de Paris, 1907) found that
about one-third of French births (32.28 per cent.) are to a
greater or less extent premature. Pregnancy is not a morbid
condition; on the contrary, a pregnant woman is at the climax of
her most normal physiological life, but owing to the tension thus
involved she is specially liable to suffer from any slight shock
or strain.

It must be remarked that the increased tendency to premature
birth, while in part it may be due to general tendencies of
civilization, is also in part due to very definite and
preventable causes. Syphilis, alcoholism, and attempts to produce
abortion are among the not uncommon causes of premature birth
(see, e.g., G.F. McCleary, "The Influence of Antenatal Conditions
on Infantile Mortality," _British Medical Journal_, Aug. 13,
1904).