tion of twins is the age of the mother.
Very extensive statistics have demonstrated that, from the earliest
child-bearing period until the age of forty is reached, the fertility of
mothers in twins gradually increases. Between the ages of twenty and
thirty, fewest wives have twins. The average age of the twin-bearer is
older than the general run of bearers. It is well known that by far the
greater number of twins are born of elderly women. While three-fifths of
all births occur among women under thirty years of age, three-fifths of
all the twins are born to those over thirty years of age. Newly-married
women are more likely to have twins at the first labour the older they
are. The chance that a young wife from fifteen to nineteen shall bear
twins is only as one to one hundred and eighty-nine; from thirty-five to
thirty-nine the chance is as one to forty-five,--that is, the wives
married youngest have fewest twins; and there is an increase as age
advances, until forty is reached.

Race seems to have some influence over plural births. They occur
relatively oftener among the Irish than among the English.

INFLUENCE OF TWIN-BEARING ON SIZE OF FAMILIES.

Do women bearing twins have in the end larger families than those never
having but one at a time? Popular belief would answer this question in
the affirmative. Such a reply would also seem to receive support from
the fact, well established, that twins are more frequently additions to
an already considerable family than they are either the first of a
family or additional to a small family. But statistics have not answered
this question as yet positively. They seem, however, in favour of the
supposition that twin-bearing women have larger families than their
neighbors.

Women are more apt to have twins in their first pregnancy than any
other, but after the second confinement the bearing of twins increases
in frequency with the number of the pregnancy. It becomes, therefore, an
indication of an excessive family, and is to be deplored.

MORE THAN TWO CHILDREN AT A BIRTH.

Cases of the birth of more than two children at a time are still less
frequently met with than twins. They are scarcely ever encountered,
excepting in women who have passed their thirtieth year. Such cases are
all more or less unfortunate both for the mother and the children.

THREE AT A BIRTH.

The births of triplets are not exclusively confined to women above
thirty years, but in those younger