omewhat similar classification has already been made by Max
Dessoir, who points out that we must distinguish between onanists _aus
Noth_, and onanists _aus Leidenschaft_, the latter group alone being of
really serious importance. The classification of Dallemagne is also
somewhat similar; he distinguishes _onanie par impulsion_, occurring in
mental degeneration and in persons of inferior intelligence, from _onanie
par evocation ou obsession_.

[346] W. Xavier Sudduth, "A Study in the Psycho-physics of Masturbation,"
_Chicago Medical Recorder_, March, 1898. Haig, who reaches a similar
conclusion, has sought to find its precise mechanism in the
blood-pressure. "As the sexual act produces lower and falling
blood-pressure," he remarks, "it will of necessity relieve conditions
which are due to high and rising blood-pressure, such, for instance, as
mental depression and bad temper; and, unless my observation deceives me,
we have here a connection between conditions of high blood-pressure with
mental and bodily depression and acts of masturbation, for this act will
relieve these conditions and tend to be practiced for this purpose."
(_Uric Acid_, 6th edition, p. 154.)

[347] Northcote discusses the classic attitude towards masturbation,
_Christianity and Sex Problems_, p. 233.

[348] _El Ktab_, traduction de Paul de Regla, Paris, 1893.

[349] Remy de Gourmont, _Physique de l'Amour_, p. 133.

[350] Tillier, _L'Instinct Sexuel_, Paris, 1889, p. 270.

[351] G. Hirth, _Wege zur Heimat_, p. 648.

[352] Fere, in the course of his valuable work, _L'Instinct Sexuel_,
stated that my conclusion is that masturbation is normal, and that
"_l'indulgence s'impose_." I had, however, already guarded myself against
this misinterpretation.

APPENDIX A.

THE INFLUENCE OF MENSTRUATION ON THE POSITION OF WOMEN.

A question of historical psychology which, so far as I know, has never
been fully investigated is the influence of menstruation in constituting
the emotional atmosphere through which men habitually view women.[353] I
do not purpose to deal fully with this question, because it is one which
may be more properly dealt with at length by the student of culture and by
the historian, rather than from the standpoint of empirical psychology. It
is, moreover, a question full of complexities in regard to which it is
impossible to speak with certainty. But we here strike on a factor of such
importance, such neglected importance, for t