The new dominion. [volume] (Morgantown, W. Va.) 1876-1904, 1885-08-29
THE HOUSE-FLY.
A Chapter on the History of This
Adjunct of Culture"
How the Fly Moves, Lives and Obtains It's
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 degree apply
to that ever-present household COM
panion. the house-hy. Wherever civil
lization penetrates, there go the honey
bee and the house-fy, 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, To
the last joint are attached two hooked
claws, and if anyone will examine the
fly's foot with 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 seerete sticky fluid. Each tenent
hair is bent near the end, beyond which
bend, says Tuffen West, sis an elastic
membranous expansion, capable of close
contact with highly polished surface,
from which very minute quantity of a
clear, transparent fluid Is emitted when
the fly is actively moving"
Mr.. West also adds, that when fly is
not making use of its cushions, as on q
surface sufficiently rough to afford it
foot-hold with its claws alone, these only
are made use of.
As early as 1867 Hooke noticed the
Importance of the grasp gained by the
claws, when drawing against the strong,
forward pointing hairs situated on the
base of each tarsal joint, whenever any
projections or yielding surface are
afforded by the object on which the fly
is walking. Hooke also believed in the
existence OF ''smoky substance on
glass;
This, says West. has been considered
mistake, land yet it is certain that
glass very frequently undergoes 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 smoky substance We're con-
densed upon it.
1t has been proved by most careful
observations, which may be readily
verified by any one DESTROYS of getting
at the truth. that this tarnish does very
materially assist a fly when in 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 fly
foot arc made. The cushions are set
down on smooth surface, perpendic-
ular or horizontal, and the numberless
tencnt hairs applied to such surface:
"a slight push forward of these, sue
coded by gentle draw backwards, at
each application, removes the air be-
tween their soft, elastic expansions and
their plane of motion, and thus firm
hold is gained. Access of air is pre-
vented by the minute quantity of moist
ure which exudes from the expanded
tips of the tenent appendages; and thus
vacuum Is formed, on the same prin-
ciple as in the atmospheric hat-peg,' the
plate holder of the photographer, or
the artificial gums of the dentist. When
the fly wishes to move leg from its
place of attachment, the claws are
brought down and pressed against the
surface; from their position they raise
the hinder part of the pulvillus (cush.
ion). where the tenent hairs are leas,
developed, first, and so on forwards. II
the claws were attached to the fifth
joint. as it has been supposed, they
could not act equally well in the way
have mentioned; and think fly wher
once stuck fast, if it had no claws, might
remain So"
1t should be noticed, as any one NAV
do, that the fly, like all insects, moves
the legs of each pair alternately in
walking After all. the pressure of the
atmosphere is the main agent by which
fly is able to adhere to perfectly
smooth surfaces.
Flies are distinguished from most 9th
or insects by having but a single pair O
wings; what corresponds to the seconc
or hinder pair in other insects being {
pair of knob-like ''balancers." Tn,
flight of the house fly is most rapid il
warm, sultry weather. We all know
how busy and pertinacious their move
monts are in dog day weather.
1t has been found that common fly
whom held captive moves its wings three
hundred and thirty times q minute
whereas q honey-Dee, whose powers o.
continued flight are much greater
moves its wings one hundred and ninet,
times In the same period. The wing
describe figure 8 in the air.
The buzz Of the fly has been carefully
studied by Landois. During fight thu
fiy's buzz or hum is in relatively low
tome: Wh0n Il II held 10 that the wing