The Washington herald., 1907-07-07

agency they effect their entrance into the
human body The older theories assumed
that stagnant water made a home for
them, and that they were inhaled in the
mists and vapors which rose from the
marsh. and possibly by the drinking OF
foul water But experiments made in try
ing to develop the parasites from stagnant
water failed 10 give the supposed results.
Mosquito Theory Revived.
Then the mosquito theory existent. and
lin vogue for some centuries. was revived,
and trials which were made. independ-
emily Of each other, added strength to the
belief that infection came from the bites
of the insect In 1894 Maj Ross was told
by Dr. Manson (now Sir Patrick Manson'
of his own theory concerning the ability
of parasites to transfer themselves from
one species Of animal to another, and ne
began to make critical examination for
himself.
When, after two and a half years Of
experimenting, he was on the point Of
giving up in despair, he was startled on
examining a new specie Of mosquito, TO
discover in its tissues the very bodies he
was in search Of. Before he could obtain
formal proof his researches were inter
fered with by his being ordered TO
place where there was little OF no ma
laria. The following year the government
Of India placed him on special duty for
the continuance of his study. and then in
few months he was able 10 establish
his conclusions. which were 10 the effect
that when mosquitoes Of particular spe-
cies suck the blood of infected men. ami
mails. or birds they draw In with It the
parasites Of malaria. and these, living and
growing in them, produce spores, which
find their way down the proboscis into
the blood of their next victim, injecting
him. Thus the mosquito takes the para
site from one infected person, and after
a week or more conveys II into the blood
Of another, probably quite healthy, indi-
vidual.
Schools Became Active.
After this discovery had been made
public. schools Of tropical medicine and
societies took it up, books and pamphlets
innumerable were written upon the sub
iect, and healthy persons volunteered
themselves to be acted upon by the eX-
perimentalists, so the new study was
prosecuted with all vigOr. One Of the
things it is most curious TO note is that
the results OF all this combined working
merely developed and added to the con-
lectures and theories of the ancients. For
example. the mosquitoes which carry
Laf,r4ur 20 a called
the anophelnes which breed mostly in
terrestrial waters-that is. in marshes
which explains the connection between
marshes and malarial fever. But it is not
the parasite causing the fever which lives
and breeds in the marsh. but the Enat OF
mosquito which is the carrier of the par
asitic poison. Where appropriate marshes
exist, these insects abound and infect
every one within their reach by inoculat-
ing them with the poison they carry from
one 10 the other IL is argued that mos
quitOes also exist and abound where there
is no malaria. and this is true. the differ
ence being that they are not anophcIiHc
mosquitoes Happily FOR us. the anophe-
line is a comparatively rare kind
Mai. Ross Remedy.
The remedy which MAJ. Ross advocates
most strongly is the tracking and drain
age Of waters and swamps which favor
the breeding Of the malaria type To
carry out sanitation in this way is not
merely TO get rid OF the mosquito itself,
but Of pests Of flies and other insects.
His plans are now being included I'm all
the schemes Of tropical sanitation, and
with the improvement In land, air, and
water, cleanliness and better housing
come as natural result