The Republican. [volume] (Oakland, Md.) 1877-current, 1885-08-15
THE HOUSE-FLY.
A Chapter on the History Of This
Adjunct of Culture"
How the Fly Moves, Lives and Obtains Its
NOurishment-The Development of
Its Wings-What Becomes of
the TOrmentors in Winter
General Points.

Some one has observed how little we
really know about our intimate friends;
even those living under the same roof.
The same remark will in a degree apply
to that eyer-present household COM
panion, the house-hy. Wherever civil
Hzation penetrates, there 90 the honey
bee and the house-hy, twin adiuncts of
the higher culture. And yet how little
is known of the life-history of the fly;
where its eggs are placed, where its
young live, upon what they live, how
they become flies, and how long they
remain with us.
If we examine one of them, it will be
seen that the fly has six LEGS, composed
of number of segments or Joints
freely movable upon each other; the toe
or tarsal joints are five in number 70
the last joint are attached two hooked
claws. and if anyone will examine the
fly foot with a microscope, he will de-
tect between the claws a little cushion
which is deeply cleft into two parts or
flaps. The under sides of the flaps
have very numerous peculiar hairs which
are Dubious at the end, and are called
"tenent-hairs. These hairs are hollow.
and sccrete a sticky fluid. Each tencnt
hair is bent near the end, beyond which
bend, says Tui1en West, lis an elastic
mcmbranOus expansion, capable of close
contact with highly polished surface.
from which very minute quantity of
clear transparent fluid is emitted when
the fly is actively moving"
Mr.. West also adds, that when llv is
not making use of its cushions as on a
surface sufficiently rough to afford it
fOot-hold with its claws alone, these only
are made use of.
As early as 1861 Hooke noticed the
importance OF the grasp gained bv the
claws, when drawing against the strong.
forward pointing hairs situated on the
base of each tarsal Joint, whenever any
projections or a yielding surface are
afforded by the object on which the nv
is walking. Hooke also believed in the
existence of Il smoky substance on
glass"
This, says West. has been considered
a mistake, land yet it is certain that
glass very frequently undergoes a slow
decomposition on its surface in a moist
atmosphere, from the excess of alkali
in its composition. Such change is
speedily produced in glass exposed to
the action Of the weather as in our
window-panes, and conveys the appear
ance as if a smoky substance were con-
densed upon it.
1t has been proved by most careful
observations which may be readily
uaritinH ht- Il g
at the truth, that this tarnish does very
materially assist a fly when in a weak
state in maintaining its hold. and in
freely moving upon the glass To keep
our windows clear for the admission of
light, it requires to be constantly re-
moved.
Opticians call similar deposition of
moisture the sweating of glass"
West further describes the way in
which the actual movements of the fy's
foot are made. The cushions are set
down on smooth surface, perpendic-
ular or horizontal, and the numberleSs
tcnent hairs applied to such surface
"a slight push forward of these. sue
ceeded by gentle draw backwards, at
each application, removes the air be-
tween their soft, elastic expansions and
their plane of motion, and thus a firm
hold is gained. Access Of air is pre-
vented by the minute quantity of moist
ure which eNudes from the expanded
tips of the tenent appcndages; and thus
vacuum is formed, on the same prn-
ciple as in the atmospheric hat-peg, the
'plate-holdcr' of the photographer, or
the artificial gums of the dentist. When
the fly wishes to move a leg from its
place of attachment, the claws are
brought down and pressed against the