The Savannah morning news., 1903-08-23

taking part in this process are known
as gametes. These gametes are the
equivalents of the sperm and germ
cells of higher animals; and d, the
result of the conjugation, is known as
a zygote or an oocyst. These oocysts
in the same mosquitoes had penetrated
the cells that line the inner surface of
the stomach.
I'm the stomach walls Of the mos
quitos killed five days after infection
the oocysts had increased very much
in size, and the single nucleus had
fragmented into more than twenty
nuclei, which were distributed through
the plasma of the oocysts. The con-
tents Of these oocysts, consisting of
the plamasa breaking up and each
fragment appropriating a nucleus, are
known as sporoblasts.
I'm the diverticulum (the commits
sion) or in the urinary tubules (myselO
of the mosquitoes killed six days after
infection, the sporoblasts were seen to
have taken a definite ovate shape and
had escaped from the oocysts. These
free sporoblasts are known technical
ly as spores.
These free spores were then found
in the upper part of the abdomen and
thorax of mosquitoes killed from six to
twelve days after infection. Near the
twelfth day they were seen in the It's
sues surrounding the salivary glands.
The mosquitoes killed on the twelfth
day after infection had these spores
in the cells Of the salivary glands, and
the spores had fragmented into an i'm
mense number of rod-sftaped bodies.
Some of these masses of rod-shaped
bodies still retained the size and shape
of the spores; others again, while re-
tanning the shape of the spores. had
increased in size so as to half fill the
cells, while again others had lost all
shape and the cells were completely
filled with these rod-shaped bodies; in-
deed, some of the cells of the glands
appeared to be one and a half times
their original size. These rod-shaped
bodies, the product of the splitting up
of the spores, are known technically
as sporozoites, or, to use popular
term, germs.
This process, from the gametes to
the sporozoites, which is very similar
to that of the malarial parasite in the
body of the mosquito, is known as the
sexual cycle of the parasite, in con-
tradistinction to the asexual or vege-
table cycle, which, with the rnalarial
parasite, occurs in the blood of the pa
tient, and which, from analogy, we can
reasonably expect ia find the parasite
undergoing in the blood of a yellow
fever patient. This asexual or vege-
table cycle consists in the segmenta-
ton of the animal and it's nucleus;
each segment, with its included nu-
cleus, constituting a new parasite.
1.-The only natural outlet for the spo-
rozoites which fill the saliavry glands
is through the ducts leading from
these glands to the proboscis of the
MOSQUITO, and when she pierces the
skin Of a non-immune and draws
blood she injects with her salivary
secretion into the blood OF the victim
a number OF sporozoites, which may
then produce the fever.
"'rhe facts which tend to prove that
this parasite is the cause OF yellow
fever may be summed up as:
"First-In the blood OF a yellow
fever patient which constituted the first
meal OF the mosquitoes there was found
this parasite In its first stage.
"SecOnd-The circle In the mosquito
which this parasite undergoes Is very
similar to that Of another disease
producing animal parasite, the plasmo-
dium malariae OF malarial fever.