Virginian-pilot. (Norfolk, Va.) 1898-1911, 1900-04-08

The Little Pests, and How They
Disseminate Malaria.
The Parasite and Its History Said to Be
long to the Animal Kingdom The
Blood Contains During Attack ofFeyer
From 100000, 900 to 1000, 900. 900 aa-
Iarial microbes.


continued prevalence OF malarial fever
was attended by the occurrence of ex-
tensive changes, apparently Of q degen-
erative character. in the physical con-
dition OF the blood. and these changes,
says the London Times. when they
were made the subjects Of investigation
by the aid of modern microscopes, were
traced to the presence az parasites as
inyariable concomitants of the disease.
Blood owes it's color to the presence of
innumerable minute bodies called it's
red corpuscles, bodies SO minute and SO
numerous that single cubic MILNE
tire of blood contains an average of
about five millions of them. and it was
within these corpuscles that the para,
sites were discovered. AIalarial feverS
are characterized by definite eXacerba-
lions and intermissions, and it soon
became apparent that these were sew
orally coincident. in point OF time, with
successive stages of the life history
OF the parasite, each attack of fever de-
noting the Matching OF new brood.
and presenting the successive stages of
shivering, of heat, and OF sweating, CO.
incidently with their growth and de-
velopment, at the conclusion of which
each corpuscle which had been invaded
by them persisted, and its function as
carrier Of oxygen to the tissues was
| abolished.
Unlike the now familiar vegetable
parasites collectively called microbes,
by which so many other diseases are
occasioned the parasite of malaria be-
longs to the animal kingdom, but, like
the microbes. its numbers increase
with amazing rapidity. Until they
| reach to q considerable amount the
parasite would not be productive of Sc
rious symptoms, but by the time that
an attack of fever Is fairly established,
these numbers often amount to some
thing like 250.000,000. and thence would
range upward to 100000, 600. 1t had
long been known that quinine was the
| most potent OF all remedies for ague,
and its administration a all sorts of
times and in all sorts of doses had
gradually led to the experimental de-
termination of the conditions of it's
greatest efficacy, but prior to the dis
covery Of the parasite, 1t was regarded
as being essentially 'anti-periodic" in
| Its effects-that Is to say, as eXerting
some rhythmical recurrence of morbid
pneumonia. The discovery of the par
aste led to the further discovery that
quinine cured ague simply by poison
ing the parasite, and that 1T was most
effective for this purpose when given
in such doses and In such q way as to
be present in the blood in sufficient
| quantity during a certain period of
| their growth. But 1t seldom killed
them all, and more usually left few
! individuals, perhaps more or less Ian
gushing, but still living and reproduce
ing their kind, and capable of giving
rise to a fresh attack of fever, even
after the lapse of many months.
| The next stage in the investigation
| was to ascertain through what channel
| the malaria parasite became introduced
| into the, human body: and DR.. Patrick
| Manson. who had previously traced an
| other form of infection to the mosquito,
was. we believe. the first to suggest
that this insect was the most probable
| delinquent. The Investigations of
Major Ross. to whose letter claiming
priority we were glad to give Insertion
| Wednesday, finally established the cor
rectness of the hypothesis. The parti-
| cular mosquito concerned is of the
| species known to naturalists as Anop-
hcles. and the evidence of the crime Is
| complete. He, or rather She for the
| ladies of the family are the sole often
| ders. is furnished with salivary glands
| which secrete the poison which she in
| 1ects-into her bites a female may be
Matched from captured larva and fed
| for the first time by being permitted 10
| bite man suffering from fever. She
| will swallow one or more of the para
| sites or their spores as part of her
meal. and. IL kept in confinement, their
| life within her body may be observed.
| They ultimately find their way from
her stomach to her salvary glands
which Secrete the poison with the
| poison into the blood of the next victim
| whom she may select or may be fur
nished with. The process can be
watched from beginning to end. and II
constitutes chain of morbid action of
| the most interesting and curious char
acter. which at the same time COM
pletely clears up the whole question of
the nature and causation of the fever.
All speculation about air about soil.
about "malarial BELTS" and the like
nave been rendered obsolete. There is
no reason to believe that the para site
finds access to the human body throu 9Th
| any other channel, or that the "gnats"
| or mosquitoes" which infest regions
| free from malaria are examples of An
| opheies If this particular insect could
be eXtirpated. there is every reason for
the hope that malarious fevers would
disappear from the earth; and. fortu-
nately. the extirpation docs not seem
likely to present any insurmountable
| difficuity. The eggs are laid in water
and the larvae. when Matched, live in
| water for about week before they as
| sumo the mosquito form. AS larvae
IKE those OF the common gnat. they
| rise to the surface of the water to
| breathe: and q. film of oil on this sur
face is speedily fatal to them, by block
| ing up their air spiracles The fully
| formed mosquito lives for many weeks.
but is not presumed to travel far, and
probably always obtains it's food with
in easy reach of It's native pool Of wa
ter. to which 1t periodically returns for
the purpose of depositing its eggs.
Much may be done. therefore, by
drying up the pools in the vicinity of
houses. or by treating them once a
week with film of kerosene oil. Much
may be done also by killing the mature