very great service, and instead of starting so late as to have no time
for walking to school or work, a certain portion of the daily journey
should be done on foot. Further, in all cases where it is possible,
team games, gymnastics, and dancing should be called in to supplement
the walk.

Headache.--Headache may be due to so many different causes that it
would be impossible in this little book to adequately consider them,
but it would not be fair to omit to mention that in many cases the
headache of young people is due to their want of spectacles. The idea
that spectacles are only required by people advanced in life is by
this time much shaken, but even now not only many parents object to
their children enjoying this most necessary assistance to imperfect
vision, but also employers may be found so foolish and selfish as to
refuse to employ those persons who need to wear glasses. The folly as
well as selfishness of this objection is demonstrated by the far
better work done by a person whose vision has been corrected, and the
absolute danger incurred by all who have to deal with machinery if
vision is imperfect. Among other causes for headache are the defects
of mouth, throat, stomach, and bowels already described, because in
all of them there is a supply of septic material to the blood which
naturally causes headache and other serious symptoms.

Abnormalities of Menstruation.--The normal period should occur at
regular intervals about once a month. Its duration and amount vary
within wide limits, but in each girl it should remain true to her
individual type, and it ought not to be accompanied by pain or
distress. As a rule the period starts quite normally, and it is not
until the girl's health has been spoiled by over-exertion of body or
mind, by unwise exertion during the period, or by continued exposure