think in this connexion. But there is a tendency to overestimate the
proportion of cases in which stimulation of the glans penis, in the
male, or the clitoris, in the female, is the exciting cause of
masturbation. In a very large number of cases of masturbation, it is not
the glans, but some other portion of the penis, which is the focus of
stimulation. In girls, also, in numerous instances, masturbation is
effected by stimulation of the labia minora, and I am inclined to
believe that the importance of the labia minora is in this respect not
inferior to that of the clitoris. In solitude, and above all in bed,
masturbation can naturally be effected much more readily. Some little
girls grasp a pillow between their legs in such a way as to give rise to
a masturbatory stimulus. Others introduce cylindrical objects into the
vagina, a practice much commoner among fully-grown girls than among
children. Still, physicians are sometimes called on to remove such
articles from the vaginae of quite little girls. But it is an error to
suppose that the hymen is frequently ruptured by practices of this kind;
the rupture of the hymen is far too painful for it to be likely to be
effected during masturbation.

Erogenic zones, that is to say, areas of the surface of the body whose
stimulation gives rise, directly or indirectly, to voluptuous
sensations, are met with often in early childhood. First of all we have
those parts of the genital organs mentioned in the last paragraph;
secondly, other regions of the body. Thus, in some individuals,
stimulation of the anal and gluteal regions gives rise to voluptuous
sensations. Freud[39] maintains that voluntary retention of the faeces is
utilised for this purpose, but this appears to me very doubtful. In many
children, however, gentle scratching of the anal region or the buttocks,
and also more powerful stimulation of the gluteal region, such as occurs
in flagellation, are associated with sexual excitement. Some children,
with this end in view, stimulate the anal region with the finger or with
some instrument. Other erogenic zones are also at times found in
children, but not often; whereas in adults such erogenic zones are
numerous, but differ greatly in different individuals. In this
connexion, I need merely allude to the production of voluptuous
sensations by tickling the nape of the neck.

Attempts have often been made to determine the comparative frequency of
masturbation in the two sexes. O