real family name, _Coccus_, which means a berry, was
suggested, by their rounded shape under the microscope, to some
poetically minded microscopist. Undesirable citizens, both of them! But
the older, or _Strepto_, cousin is by far the more dangerous character
and desperate individual, giving rise to and being concerned in nearly
all the civilized and dangerous wound-fevers--septicaemia, erysipelas,
etc. _Staphylococcus_ is a milder and less harmful individual, seldom
going farther than to produce the milder forms of festering,
discharging, refusing to heal, pustules, etc. He is not to be given a
yard of leeway, however, for if he can get a sufficient number of dirty
wounds to run through, he can work himself up to a high degree of
virulence and poisoning power. Indeed, this faculty of his may possibly
furnish a clew as to how these pus-makers developed their power of
living in wounds, and almost nowhere else. There is another cousin also,
in the group, called _Staphylococcus pyogenes albus_, to distinguish him
(_albus_, "white") from the other two, who have the tag name aureus
(golden). He is an almost harmless denizen of the surfaces of our
bodies, particularly the mouths of the sweat-ducts, and the openings of
the hair follicles. Under peculiarly favorable circumstances, such as a
very big wound, an aggravated chafe, or the application of that
champion "bug-breeder," a poultice, he may summon up courage enough
to attack some half-dead skin-cells and make a few drops of pus on
his own account. He is the criminal concerned in the so-called
stitch-abscesses, or tiny points of pus which form around the stitches
of a big wound and in some of the smaller pimples which turn to
"matter." It is conceivable that this feeble and harmless white coccus
may at some time have been accelerated under favorable circumstances to
where he was endowed with "yellow" powers, and even, upon another turn
of the screw, with strepto-virulence. But this is a mere academic
question. Practically the only thing needful is to keep all the rascals
out of every wound.

Now comes the question, how is this to be done? Fortunately it is not
necessary to hunt out and destroy the pus-germs in their breeding-places
outside of the human body. As we have seen, they do not long retain
their vitality out of doors, or as a rule even in the dust of rooms and
dirt of houses, unless the latter have been recently contaminated with
the dressings of, or discharges fr