ense of the surrounding tissues, and
behold, a new cancer, or "secondary nodule," is born (_metastasis_).

In fact, it is a genuine "animal spore," or seed-cell, capable of taking
root and reproducing its kind in any favorable soil; and, unfortunately,
almost every inch of a cancer patient's body seems to be such. It is
merely a question of where the spore-cells happen to drift and lodge.
The lymph-nodes or "settling basins" of the drainage area of the primary
cancer are the first to become infected, probably in an attempt to check
the invaders; but the spores soon force their way past them toward the
central citadels of the body, and, one after another, the great, vital
organs--the liver, the lungs, the spleen, the brain--are riddled by the
deadly columns and choked by decaying masses of new cells, until the
functions of one of them are so seriously interfered with that death
results.

Obviously, this is a totally different process, not merely in degree,
but in kind, from anything that takes place as a result of the invasion
of the body by an infectious germ or parasite of any sort. There is a
certain delusive similarity between the cancer process and an infection.
But the more closely and carefully this similarity is examined the more
superficial and unreal does it become. The invading germ may multiply
chiefly at one point or focus, like cancer, and from this spread
throughout the body and form new foci, and may even produce swarms of
masses of cells resembling tumors, as, for instance, in tuberculosis and
syphilis. But here the analogy ends.

The great fundamental difference between cancer and any infection lies
in the fact that, in an infection, the inflammations and poisonings and
local swellings are due solely and invariably to the presence and
multiplication of the invading germs, which may be recovered in millions
from every organ and region affected, while swellings or new masses
produced are merely the outpouring of the body-cells in an attempt to
attack and overwhelm these invaders. In cancer, on the contrary, the
destroying organism is a group of perverted body-cells. The invasion of
other parts of the body is carried out by transference of their bastard
and abortive offspring. Most significant of all, the new growths and
swellings that are formed in other parts of the body are composed, not
of the outpourings of the local tissues, but of _the descendants of
these pirate cells_. This is one of the most si