tament,
and write the other substitution, wherein a man is named heir on the
succession and death of the pupil, separately on the lower part of the
will; and this lower part he should tie with a separate cord and fasten
with a separate seal, and direct in the earlier part of the will that it
shall not be opened in the lifetime of the son before he attains the age
of puberty. Of course a substitution to a son under the age of puberty
is none the less valid because it is a integral part of the very will
in which the testator has instituted him his heir, though such an open
substitution may expose the pupil to the danger of foul play.

4 Not only when we leave our inheritance to children under the age
of puberty can we make such a substitution, that if they accept the
inheritance, and then die under that age, the substitute is their heir,
but we can do it when we disinherit them, so that whatever the pupil
acquires by way of inheritance, legacy or gift from his relatives or
friends, will pass to the substitute. What has been said of
substitution to children below the age of puberty, whether instituted or
disinherited, is true also of substitution to afterborn children.

5 In no case, however, may a man make a will for his children unless
he makes one also for himself; for the will of the pupil is but a
complementary part of the father's own testament; accordingly, if the
latter is void, the former will be void also.

6 Substitution may be made either to each child separately, or only to
such one of them as shall last die under the age of puberty. The first
is the proper plan, if the testator's intention is that none of them
shall die intestate: the second, if he wishes that, as among them, the
order of succession prescribed by the Twelve Tables shall be strictly
preserved.

7 The person substituted in the place of a child under the age of
puberty may be either named individually--for instance, Titius--or
generally prescribed, as by the words 'whoever shall be my heir'; in
which latter case, on the child dying under the age of puberty,
those are called to the inheritance by the substitution who have been
instituted heirs and have accepted, their shares in the substitution
being proportionate to the shares in which they succeeded the father.

8 This kind of substitution may be made to males up to the age of
fourteen, and to females up to that of twelve years; when this age is
once passed, the substitution becomes void.