with very few exceptions, there appears a more or less intense brown
line which runs downward from the navel in the middle of the abdomen.
Sometimes, though not very often, small dark areas, which have been
called "liver spots," appear elsewhere over the body. The name is
unfortunate, for the spots do not indicate a disorder of the liver.

At present it is generally admitted that alterations in the color of
the skin during pregnancy are due to deposits of iron. This mineral
substance, among others, as we have learned, is required for the
development of the embryo. The child is born with a supply of iron
calculated to meet its needs for about a year. Such a reserve is
necessary, as Bunge has pointed out, because human milk does not
contain enough iron to satisfy the infant's requirements. During
pregnancy, therefore, the mother's blood transports iron to the
placenta, where it can be absorbed into the child's system; and while
being thus transported some of it is deposited in the maternal
tissues. The deposits are especially frequent, as I have mentioned,
in the middle line of the abdomen, on account of the arrangement of
the blood vessels there. Deposits elsewhere may depend upon other
conditions; but whatever their cause the pigmentation vanishes a
short time after the birth.

Alterations in the color of the skin have no effect upon its
excretory function, which, indeed, generally becomes more active
during pregnancy. According to one estimate, the average person
possesses twenty-eight miles of sweat glands. If these figures are
not sufficient to demonstrate the importance of the skin as an
excretory organ, surely no one will fail to be impressed by the
tragic result which in one case followed throwing all the sweat
glands out of action. This was brought about in the case of a young