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end of the stylo-hyoidaeus muscle ; and from the lower edge
of this tendon, some fibres seem to go off, which degenerate
into a kind of fascia, that binds it to the os-hyoides ; and
some of it goes across the lower part of the mylo-hyoideus
binding the os-hyoides by a kind of belt. At this part the
tendon becomes a little broader, makes a turn upwards, in-
wards, and forwards, and gives origin to the anterior belly,
which passes on in the same direction, to the lower part of
the chin, where it is inserted tendinous and fleshy, in a slight
depression on the under, and a little on the posterior part of
the lower jaw, almost contiguous to its fellow. Besides the
attachment of the middle tendon to the os-hyoides, there is
a ligamentous binding, which serves, in some measure, as a
pulley. This is more marked in some subjects than in others
and this depends on the strength of the tendinous expansion
which binds the tendon of the digastricus to the os-hyoides.
When we say that these parts are attached to the os-
hyoides, we do not mean that they can be traced quite into it
like some other tendons in the body; but the os-hyoides
seem to be the most fixed point of attachment. Very often
we find two anterior bellies to each muscle ; the uncommon
one, which is the smallest ; does not pass to the chin, but
joins with a similar portion of the other side, in a middle
tendon, which is often fixed to the os-hyoides. At other
times, we find such a portion on one side only; in which
case it is commonly fixed to the middle tendon of the mylo-
hyoideus.
The use of these muscles with regard to the lower jaw,
is principally to depress it ; but according as one acts a little
more forcibly than the other, it thereby gives the jaw a small
rotation ; and becomes, in that respect a kind of antagonist
to the pterygoideus externus. Besides depressing the lower
jaw, when we examine the dead body they would appear to
35
end of the stylo-hyoidaeus muscle ; and from the lower edge
of this tendon, some fibres seem to go off, which degenerate
into a kind of fascia, that binds it to the os-hyoides ; and
some of it goes across the lower part of the mylo-hyoideus
binding the os-hyoides by a kind of belt. At this part the
tendon becomes a little broader, makes a turn upwards, in-
wards, and forwards, and gives origin to the anterior belly,
which passes on in the same direction, to the lower part of
the chin, where it is inserted tendinous and fleshy, in a slight
depression on the under, and a little on the posterior part of
the lower jaw, almost contiguous to its fellow. Besides the
attachment of the middle tendon to the os-hyoides, there is
a ligamentous binding, which serves, in some measure, as a
pulley. This is more marked in some subjects than in others
and this depends on the strength of the tendinous expansion
which binds the tendon of the digastricus to the os-hyoides.
When we say that these parts are attached to the os-
hyoides, we do not mean that they can be traced quite into it
like some other tendons in the body; but the os-hyoides
seem to be the most fixed point of attachment. Very often
we find two anterior bellies to each muscle ; the uncommon
one, which is the smallest ; does not pass to the chin, but
joins with a similar portion of the other side, in a middle
tendon, which is often fixed to the os-hyoides. At other
times, we find such a portion on one side only; in which
case it is commonly fixed to the middle tendon of the mylo-
hyoideus.
The use of these muscles with regard to the lower jaw,
is principally to depress it ; but according as one acts a little
more forcibly than the other, it thereby gives the jaw a small
rotation ; and becomes, in that respect a kind of antagonist
to the pterygoideus externus. Besides depressing the lower
jaw, when we examine the dead body they would appear to
