old many thousands of them. Under the microscope they show
a sort of head and tail like a pollywog. They are very much alive and
move by a rapid wiggling of the tail part.

Leading from each testicle is a tube called the vas deferens, through
which the sperm goes at the time of the sex act on its way out to
meet the ovum in the woman's body. On the way it is joined by two
other liquids, one secreted by the seminal vesicles (of which there
are two) and the other by the prostate gland. These three liquids
together form the semen, which at the times of sexual excitement is
forced out through the penis into the vagina of the woman.

You will notice that the woman has separate tubes for the urine
(waste water) and the sex function, but the man uses the same tube
for both: that is, in the woman the bladder which holds the urine is
emptied by a separate tube, the urethra, while in the man the urethra
not only empties the bladder, but it also carries the semen.

The use of the seminal vesicles and the prostate gland is to supply a
means of nourishment for the spermatozoa until they reach the ovum,
which may not be for several days after the semen is expelled into
the vagina.

Then there are two small glands called Cowper's glands, which make
the passage in the penis alkaline, as the spermatozoa can only remain
alive in an alkaline secretion and the urine is acid, so always just
before the penis forces out the semen, the secretion from Cowper's
glands goes ahead to protect the sperm from being destroyed by any
remaining traces of the acid urine.

At the end of the penis is a fold or cap of skin, the prepuce, which
the doctor often removes for the sake of the boy's health, a process
called circumcision, and it is a great relief to boys whose prepuce
or foreskin is too tight as to make difficulty in keeping clean. All
Jewish babies are regularly circumcised, a custom dating way back to
Bible times.

There is a constant internal secretion from the testicles of a man
just as from the ovaries of a woman, and it has the same beneficial
effect on the whole being. It makes a boy what we call manly or
virile. The value of the internal secretions of the sex organs in
both boys and girls is so great that for that reason, if for no
other, the whole sex machinery must be kept in perfect health.

Boys have a certain discomfort to bear which is difficult for them
just as menstruation is difficult for girls. But by knowing the
meaning