issues had only the original dose of
microbes to deal with, the warfare between health and disease would be
less uncertain in outcome. Victory would usually be on the side of the
tissues and health. The immediate cause of the pathogenic influence is
probably the chemical excretions which are given out by these
microscopic organisms. All plants and animals require a certain number
of substances to be taken into their organisms for preservation of
their vital activities. After these substances have been utilized
there occurs a sort of excretion of other chemical products. It is
probably the excretions of many millions of micro-organisms,
circulating in the blood, which give rise to the disease
characteristic of the fungus with which the animal has been infected.
The condition called sapraemia, or septic intoxication, for example, is
undoubtedly due to the entrance of the excretory products of
putrefaction bacteria into the circulation. This can be proved by
injecting into an animal a small portion of these products obtained
from cultures of germs of putrefaction. Characteristic symptoms will
at once be exhibited.

Septicaemia is a similar condition due to the presence of the
putrefactive organisms themselves, and hence of their products, or
ptomaines, also in the blood. The rapidity of their multiplication in
this albuminous soil and the great amount of excretion from these
numerous fungi make the condition more serious than sapraemia.
Clinically, the two conditions occur together.

The rapidity with which symptoms may arise after inoculation of small
wounds with a very few germs will be apparent, when it is stated that
one parasitic plant of this kind may, by its rapidity of
multiplication, give rise to fifteen or sixteen million individuals
within twenty-four hours. The enormous increase which takes place
within three or four days is almost incalculable. It has been
estimated that a certain bacillus, only about one thousandth of an
inch in length, could, under favorable conditions, develop a brood of
progeny in less than four days which would make a mass of fungi
sufficient to fill all the oceans of the world, if they each had a
depth of one mile.

Bacteria are present everywhere. They exist in the water, earth, air,
and within our respiratory and digestive tracts. Our skin is covered
with millions of them, as is every article about us. They can
circulate in the lymph and blood and reach every tissue and part of
ou