when kissed on the lips by a man, owing to
the conviction that she had thereby lost her virtue. Although the lips
occupy this highly important position as a secondary sexual focus
in the sphere of touch, the kiss is--unlike _cunnilingus_ and
_fellatio_--confined to man and, indeed, to a large extent, to civilized
man. It is the outcome of a compound evolution which had its beginning
outside the sphere of touch, and it would therefore be out of place to
deal with the interesting question of its development in this place. It
will be discussed elsewhere.[18]

There is yet another orificial frontier region which is a highly important
tactile sexual focus: the nipple. The breasts raise, indeed, several
interesting questions in their intimate connection with the sexual sphere
and it may be worth while to consider them at this point.

The breasts have from the present point of view this special significance
among the sexual centres that they primarily exist, not for the contact of
the lover, but the contact of the child. This is doubtless, indeed, the
fundamental fact on which all the touch contacts we are here concerned
with have grown up. The sexual sensitivity of the lover's lips to
orificial contacts has been developed from the sensitivity of the infant's
lips to contact with his mother's nipple. It is on the ground of that
evolution that we are bound to consider here the precise position of the
breasts as a sexual centre.

As the great secreting organs of milk, the function of the breasts must
begin immediately the child is cut off from the nutrition derived from
direct contact with his mother's blood. It is therefore essential that the
connection between the sexual organs proper, more especially the womb, and
the breasts should be exceedingly intimate, so that the breasts may be in
a condition to respond adequately to the demand of the child's sucking
lips at the earliest moment after birth. As a matter of fact, this
connection is very intimate, so intimate that it takes place in two
totally distinct ways--by the nervous system and by the blood.

The breasts of young girls sometimes become tender at puberty in
sympathy with the evolution of the sexual organs, although the
swelling of the breasts at this period is not normally a
glandular process. At the recurring periods of menstruation,
again, sensations in the breasts are not uncommon.

It is not, however, until impregnation occurs that real