rd,
and a matter of painfully familiar experience. Scarcely an organ in the
body escapes damage, though this may not be discovered till long after
the "fever-and-ague" has been recovered from.

As the parasite breeds in the red cells of the blood, naturally its
first effect is to destroy huge numbers of these, producing the typical
malarial _anaemia_, or bloodlessness. Instead of 5,000,000 to the cubic
centimetre of blood the red cells may be reduced to 2,000,000 or even
1,500,000. The breaking down of these red cells throws their pigment or
coloring-matter afloat in the blood; and soaking through all the tissues
of the body, this turns a greenish-yellow and gives the well-known
sallow skin and yellowish whites of the eyes of swamp-dwellers and
"river-rats."

The broken-down scraps of the red blood-cells, together with the toxins
of the parasite, are carried to the liver and spleen to be burned up or
purified in such quantities that both become congested and diseased,
causing the familiar "biliousness," so characteristic of malaria.

The spleen often becomes so enormously enlarged that it can be readily
felt with the hand in the left side below the ribs, so that it is not
only relied upon as a sign of malaria in doubtful cases, but has even
received the popular name of the "ague-cake" in malarious districts.

So full is the blood of the parasites, that they may actually choke up
the tiny blood-vessels and capillaries in various organs, so as to block
the circulation and cause serious and even fatal congestions.
Obstructions of this sort may occur in the brain, the liver, the coats
of the stomach, or intestines, and the kidneys; and they are the chief
cause of the deadly "congestive chills," or pernicious malarial
paroxysms, which we have alluded to.

The kidneys are particularly liable to be attacked in this way; indeed,
one of their involvements is so serious and fatal in the tropics as to
have been given a separate name, "Blackwater fever," from the quantities
of broken-down blood which appear in and blacken the urine.

The vast majority of attacks of malaria are completely recovered from,
like any other infection, but it can easily be seen what an injurious
effect upon the system may be produced by successive attacks, keeping
the entire body saturated with the poison; while there is serious risk
of the parasite sooner or later finding some weak spot in the
body,--kidney, liver, nervous system,--where its incess