enomena of Blushing--Influences
Which Modify the Aptitude to Blush--Darkness, Concealment of the Face,
Etc.

IV.

Summary of the Factors of Modesty--The Future of Modesty--Modesty an
Essential Element of Love.

THE PHENOMENA OF SEXUAL PERIODICITY.

I.

The Various Physiological and Psychological Rhythms--Menstruation--The
Alleged Influence of the Moon--Frequent Suppression of Menstruation among
Primitive Races--Mittelschmerz--Possible Tendency to a Future
Intermenstrual Cycle--Menstruation among Animals--Menstruating Monkeys and
Apes--What is Menstruation--Its Primary Cause Still Obscure--The Relation
of Menstruation to Ovulation--The Occasional Absence of Menstruation in
Health--The Relation of Menstruation to "Heat"--The Prohibition of
Intercourse during Menstruation--The Predominance of Sexual Excitement at
and around the Menstrual Period--Its Absence during the Period Frequently
Apparent only.

II.

The Question of a Monthly Sexual Cycle in Men--The Earliest Suggestions of
a General Physiological Cycle in Men--Periodicity in Disease--Insanity,
Heart Disease, etc.--The Alleged Twenty-three Days' Cycle--The
Physiological Periodicity of Seminal Emissions during Sleep--Original
Observations--Fortnightly and Weekly Rhythms.

III.

The Annual Sexual Rhythm--In Animals--In Man--Tendency of the Sexual
Impulse to become Heightened in Spring and Autumn--The Prevalence of
Seasonal Erotic Festivals--The Feast of Fools--The Easter and Midsummer
Bonfires--The Seasonal Variations in Birthrate--The Causes of those
Variations--The Typical Conception-rate Curve for Europe--The Seasonal
Periodicity of Seminal Emissions During Sleep--Original
Observations--Spring and Autumn the Chief Periods of Involuntary Sexual
Excitement--The Seasonal Periodicity of Rapes--Of Outbreaks among
Prisoners--The Seasonal Curves of Insanity and Suicide--The Growth of
Children According to Season--The Annual Curve of Bread-consumption in
Prisons--Seasonal Periodicity of Scarlet Fever--The Underlying Causes of
these Seasonal Phenomena.

AUTO-EROTISM: A STUDY OF THE SPONTANEOUS MANIFESTATIONS OF THE SEXUAL
IMPULSE.

I.

Definition of Auto-erotism--Masturbation only Covers a Small Portion of
the Auto-erotic Field--The Importance of this Study, especially
To-day--Auto-erotic Phenomena in Animals--Among Savage and Barbaric
Races--The Japanese _rin-no-tama_ and other Special Instruments for
Obtaining Auto-erotic Gratification--Abuse of the