The Lambertville record. [volume] (Lambertville, N.J.) 1872-1968, 1883-03-14
MISCELLANY.
FACTS ABOUT FLIES.
How They Lay Eggs and Hatch Theit
Young.

HOW Tney Lay riggs and Hatch Tneu
Young.
The most persistent companion of man Is,
perhaps, the house fly. 1t has followed him
everywhere in.his own conveyances, and is
found, SO far as we know, wherever civilized
man has established himself Our American
house fly was described as distinct species
(nauscG haTpyia) by Harris, but Packard
found it, after critical comparisons, specid-
cally identical with the linnean species Al
ready, with the growing warmth of the
spring months the fiy begins to
show its familiar form in our houses and to
inspire the careful housekeeper with feelings
anything but agreeable. Whence comes it
How has it passed the winter? Such ques.
tions are often asked Let us answer them.
Not all who have watched the fly posing or
darling noiselessly and gracefully in mid-air
or deftly making his toilet have realized that
al one time it was a crawling maggot, as
unlike its perfect self as two things well can
be. The eggs are about foLr-hundredths of
an inch long, one-fourth as wide, dull white
in color, and pitted with elongate, hexagonal
depressions-mere whitish specs to the un-
aided eye, laid in little agglutinated pileg in
warm manure or in decomposing vegetation,
especially that about our stables and barn
yards. From eighty to one hundred are laid
at time, and probably at three or four Diff
erent intervals by the same fly, though on
this point we have no exact data. Within
twenty-four hours in summer they hatch
into footless Nuggets, which, after rioting in
filth till their tender skins seem ready to
burst from repletion, become full fed in less
than week, and descending into the earth
or sheltering under some old board, contract
to brown, shining objects, rounded at both
ends and technically known as puparia
Within the darkness of this hardened skin
profound changes rapidly take place, and
the insect passes through the pupa to the
perfect state, and finally, in about five days,
the anterior end of the puparium is pushed
off and the fly quickly crawls out. At first
its parts are pale and soft and its wings are
crimpled and useless but these soon expand,
and, suddenly, without practice or teaching,
the new-hedged fly wings its way to your
table to mock your pleasure-to share
your repast The length of time required
from Matching to maturity varies with the
season and temperature; but will not exceed
ten days in midsummer, while the life OF
the perfect fly lasts about three weeks at the
same season. As cold weather approaches
propagation ceases and the older flies perish.
few of the more vigorous females, how
IN
in state of torpor, they survive till the en-
suing season-links 'twixt the summer gone
by and to come. The insect may also hi
bernate in the pupa state in the ground, as l
have found the puparia quite late in the fall
In rooms kept continuously warm, or in
southern ATTITUDES, the fly remains active all
winter, and our palace sleeping cars bring
them daily to US from Florida during the
coolest months of the year. Most of the
old authors tell us that the fly walks on the
ceiling and ip others ways defes the laws Of
gravitation by suction. You viii notice
from the figure of the foot of the fleshfy (and
the one of the house-1y has a similar con.
strpction) that it ends in pair of strong
hooks and pair of pads or cushions, tech.
nically termed pulvilli. These were sup
posed to act as sucking disks by creating a
vacuum, on the same principle as does the
piece of circular leather used by school boys
for similar purpose. In reality, however,
these pads are beset with innumerable knot
ted hairs, which are kept moist by an exud-
ing fluid. In short, we have here repeti-
ton, after fashion, of the ambulacral suck
ers Of the starfish. The smoother the sur
face the greater the adhesion of the dig
ituli This you will at once understand by
gently pressing or drawing the moist finger
ends over glass window or other polished
surface. The adhesion is very sensible,
whereas on rougher surface, like cloth or
whitewashed wall, there will be none. On
such surfaces the tarsal hooks, by catching
in the minutest irregularity, take the place Of
the pads in assisting the fys locomotion.--
Boston Traveller.