that
the defeated soldiers are apt to be in poorer physical condition to
begin with; that they have often been cut off from their base of
supplies, have made desperate forced marches without food or shelter in
the course of their retreat; and, until within comparatively recent
years, were never half so well treated or well fed as their captors.

As the invading germs pass into the body, they travel most commonly
through the lymph-channels and skin; are arrested and threatened with
destruction by the so-called lymphatic glands, or lymph-nodes. This is
why, if you have a festering wound or boil on your hand or wrist, the
"kernels" or lymph-nodes up in your armpit will swell and become
painful. If the lymph-nodes can conquer the germs and eat them up, the
swelling goes down and the pain disappears. But if the germs, on the
other hand, succeed in poisoning and killing the cells of the body,
these latter melt down and turn to pus, and we get what we call a
"secondary abscess."

The next commonest point of attack of these pus-germs, if they once get
into the body, and by far the most dangerous, is the heart, as in
rheumatism and other fevers. Some will also attack the kidneys, giving
rise to albumin in the urine, while others attack the membranes of the
joints (_synovia_) and cause suppuration of one or more joints in the
body, which is very apt to be followed by very serious stiffening or
crippling. So that, common, and, in many instances, comparatively mild
as they are, the pus-germs in the aggregate are responsible for a very
large amount of damage to the human body.

This is the way the _streptococcus_ and _staphylococcus_ behave in an
open wound, or sore; but they have two other methods of operating which
are somewhat special and peculiar. One of these is where the germ digs
and burrows, as it were, underground, in a limited space, resulting in
that charming product known as a boil, or a carbuncle. The other, where
it spreads rapidly over the surface just under the skin, after the
fashion of the prairie fire, producing _erysipelas_. In the first of
these he behaves like the famous burrowing owl of our Western plains,
who forms, with the prairie-dog, the so-called "happy family." He never
makes his own burrow, he simply uses one which is already provided for
him by nature, and that is the little close-fitting pouch surrounding
the root of a hair. Whether the criminal is a harmless native white
coccus which has suddenl