y to
obliterate the larger monthly rhythm.

However constituted, there seems little doubt that a physiological weekly
cycle really exists. This was, indeed, very clearly indicated many years
ago by the observations of Edward Smith, who showed that there are weekly
rhythms in pulse, respiration, temperature, carbonic acid evolution, urea,
and body-weight, Sunday being the great day of repair and increase of
weight.[126]

In an appendix to this volume I am able to present the results of another
long series of observations of nocturnal ecbolic manifestations carried
out by Mr. Perry-Coste, who has elaborately calculated the results, and
has convinced himself that on the basis of a strictly lunar month, thus
abolishing the disturbing influence of the weekly rhythm, which in his
case also appears, a real menstrual rhythm may be traced.[127]

It does not appear to me, however, even yet, that a final answer to the
question whether a menstrual sexual rhythm occurs in men can be decisively
given in the affirmative. That such a cycle will be proved in many cases
seems to me highly probable, but before this can be decisively affirmed it
is necessary that a much larger number of persons should be induced to
carry out on themselves the simple, but protracted, series of observations
that are required.

Since the first edition of this volume appeared, numerous series
of ecbolic records have reached me from different parts of the
world. The most notable of these series comes from a professional
man, of scientific training, who has for the past six years lived
in different parts of India, where the record was kept. Though
the record extends over nearly six years, there are two breaks in
it, due to a visit to England, and to loss of interest. Both
involuntary and voluntary discharges are included in the record.
The involuntary discharges occurred during sleep, usually with an
erotic dream, in which the subject invariably awaked and
frequently made an effort to check the emission. The voluntary
discharges in most cases commenced during sleep, or in the
half-waking state; deliberate masturbation, when fully awake, was
comparatively rare. The proportion of involuntary to more or less
voluntary ecboles was about 3 to 1. A third kind of sexual
manifestation (of frequency intermediate between the other two
forms) is also included, in which a high degree of erethism is