New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1901-10-06
MOSQUITOES AND DISEASE.
MICROSCOPICAI. EXAMINATION OF THE
INSECT FAILS TO REVEAL
POISON GLAND.

r. W. Leggett announced at meeting of the
New-York Mcroscopical Society. held at No. ga
Madson-ave. Friday night that he had made
microscopic examinations OF the internal organs Of
mosquitoes without finding any poison gland In
any of the insects. He read a paper on THE
Digestive Canal OF Mosquito" 1t was illustrated
with the microscopic slides. In speaking about his
examinations he said:
Last spring, when the papers became quite &C
short paper before this society In which tried 10
e habts and IN Internal Of this
sect No fresh specimens were then to be OBJ
that when this pest made its appearance in the
summer would devote time and study to his IN
OF course. 1 found this more difficult than ex-
pected It. was one thing to hear mosquito; an
be injured. but killed instantly before its parts
It to be mnst be- just strong
70 harden but not contract and the paraftne must
would not drag instead of cutting However: pa
thence and perseverance overcome most difficulties
one hundred ana afty mossaltoss: 49,. ~
ry which eq cut rs s gh she nand Il
the two parts arranged like beams with double
opening in the middle through its entire length
OF course this explained how the blood entered the
the mouth to the neck. and found three tubes. one
de c ss sask the
Ing went into the thorax while the two others
head and passed from there to the clypeus These
were the only openings through the head.
l then cut a transverse section through the
centre of the head. from the biting parts to the
thorax, and found two bulbs connected by a tube
One of them at the back OF the head. quite
large. dark brown. and formed of three pieces
while the other bulb was smaller, sioped down
ward and transparent. Into this oulo was
fastened the main lance abrum. then cut
d head at right angles to the last and found that
the larger bulb attached TO the sides or the
head by muscles while the smaller and trans
doubtedly the pump one set of muscles being use
to open, the other TO close the bulb, thus drawing
up the blood by air pressure.
Referring 10 the poison gland he said:
This gland may be in the thorax and may Yet
Ind Il, But why should there be a poison glandF
We dealing with mouth parts. not with a
sting. which is a weapon OF offence and defence
Now, the question is the old one How does the
mosquito carry disease from person to person, as
claimed unless II DO by the aid of the missing
gland? OF course II the pump sucks there must
be valve to prevent Its leaking when the pulD Is
quito leaking at the mouth. so the germ cannot
pass out that way because there is no thorough
fare.
How the poison gets into the wound is subject
good another. and l venture to make one. The
so-cailed poison, IL me. is the saliva, and
is possibly used. alleged to inflame and enlarge
the wound. II is forced down and out by the me-
the smaller bulb by the forcing into the flesh OF
the main lance and sete. This IL. think, rendered
probable by the shape OF the smaller setee where
they join the smaller bulb and the clypeus.
While my summer vacation many be-
came Interested in what l was doing, and I
brought home many specimens Of mosquitoes.
also discovered that IN the case of eight adults
and many children who suffered the mosquito to
Does the mosquito absorb It's own poison when
disturbed?