aracter they are not so noisily
obtruded on the public notice as are certain other widely advertised and
reputedly scientific works. In his various books, and above all in his
six volumes entitled _Studies in the Psychology of Sex_ (F. A. Davies
Company, Philadelphia, Pa.), as a part of his general contributions to
our knowledge of the sexual life, Havelock Ellis records numerous
observations relating to the years of childhood; especially valuable in
this connexion are the biographies given in the third volume of the
above-mentioned _Studies_.

A valuable source of data for our field of inquiry exists in the form of
unpublished diaries, autobiographies, and albums, which are not
accessible to the general public. I have myself had the opportunity of
studying a number of records of this nature, and have formed the opinion
that a quantity of invaluable material lies hidden in these recesses. I
may add that the records I have been able to use have not only related
to living persons; in addition, I have been able to study a number of
albums and diaries dating from an earlier day. These have remained
unpublished, in part because they appeared to be of interest only to the
families of the writers, and in part because many of them were in
intention purely private memoranda, a written record for the sole use of
the writer.

Speaking generally, however, this province of research has received but
little scientific attention; and of comprehensive studies, intended to
throw light on every aspect of the sexual life of the child, not a
single one is known to me.

Chapter II

THE SEXUAL ORGANS--THE SEXUAL IMPULSE

A proper understanding of physiological functions is based upon
anatomical knowledge of the organs concerned. For our purpose,
therefore, a knowledge of the sexual organs of the child is essential.
The proper course, in this instance, appears to be to start with an
account of the adult organs, and then to describe the distinctive
characteristics of the same organs in the child. Let us, then, begin
with the organs of the adult man.

The _membrum virile_ or _penis_ is visible externally, and behind it is
situated the scrotum. Within this latter are two ovoid structures, named
_testicles_ or _testes_. Each testicle is enveloped in a fibrous
capsule, known as the _tunica albuginea_, from which fibrous _septa_
pass into the interior of the organ, thus dividing it into a number of
separate _lobules_. Each lobule is