New-York tribune., 1910-07-17


they are by no means alike. Some are plain
brown, some black and white, some yellow
or IT1descent, gorgeous fellows, spotted and
streaked IN all sorts of combinations Some,
like the common marsh mosquito (Cuier
S0AiCltGRS) have striped legs In size they
vary from tiny chaps an eighth Of an inch
long TO giants half an inch IN lenqth. such as
the far famed Jersey gallinippers (Psoyo-
bk0rG ciiIdtd and Ps0rObhorG hozuqydii).
which are actually able to make an effective
punCture through q coat. waistCOat. and two
shirts ithls on authority OF Dr.. Tohn B
Smith, State EntOmologist Of New Tersev)
A Ii OF this seems very curious; but in the
meantime those unfortunate wrigglers
have been waiting IN the glass lar for some
thing to happen 10 them. They are lively
httle fellows, and are getting ready to un-
deTgo q remarkable transformation. After
changing their skin three times. they as
surne, at the end of about two weeks, the
pupa form, looking to the naked eve more
Ike tat commas than anything else; and in
tins stage they are comparatively inert.
floating at or close to the surface OF the wa
ter, and lodging downward with absurd
Jerks OF their tails when disturbed.
When one Of these pupe IS examined TN
der the microscope, however, 1t IS seen TO be
nothing more nor less than a sort of case. in
which, Tor temporary purpose Of Nature.
The adult mosquito IS folded up and packed
The observer can clearly distinguish the
eyes, the legs, and the wings Of the full
ttedged insect that IS to be, the abdomen of
the latter being inClosed in the tail Of the
pupa.
After two or three days spent in this pupa
case, the mosquito splits It open. and. using
l1ta III 81
stand until its wings are dry, it then flies
away. Thus all the "skeets - evolved from
the Wr1gglers IN the glass lar would make
their escape, If the receptacle was not kept
covered with a piece OF gauze. fastened with
a string or q rubber band. As it IS, they. are
captured one after another by the simple
eXpedlent OF poking the open end Of glass
test tube into the Jar. Each insect. being
obliged by little manipulation TO enter the
mouth OF the test tube, flies upward to seek
the light, and IS promptly imprisoned by
plug Of raw cotton.
II the mosquitoes thus reared are wanted
merely for preservation as specimens, or for
examination with the microscope, Il is easy
to kill them by exposing them TO the fumes
OF chlorotorm or cyanide OF potash; but
they may be kept alive in suitable recepta-
cles, or may even be transferred 70 homeo-
keit-l-A lei4S anu >CiiL LN Jt'~- IL Lllall!g
tubes. Before mailing them. however. the
cotton plugs in the walls must be dampencd.
else they VIII dry up and die.
When, for the purpose Of diagnosing a
case Of malaria. mosquitoes are used TO obtain
samples Of the patients blood, the insects
are afterward killed and their stomachs and
Salivary glands examined under microscope.
10 find out If they contain any Of the typical
malaria microbes, or zygOtes. II microbes
appear, the character OF the trouble is mani
fest.
But It IS obvious that wild mosquitoes will
not serve, inasmuCh as they are more or less
likely to be infected beforehand. The IN
seccs utilized IN this way must be Matched
and reared IN the laboratory, TO make sure
that they have never drunk blood. # they
nave not, they cannot possibly be infected,
because It IS only through this means that
they can get malaria. We are accustomed
TO say that mosquitoes inoculate US with the
disease in question; but in reality We give
malaria to them.
For the purpose Of malaria diagnosis, of
course, the Anopheles, or malaria mosquito.
and none other, must be employed, because