The Portland daily press., 1898-07-16
HISTORY OF THE HoRsEFLY.
The Most Ancient of insects, BE Is Still a
Mystery.
(Kansas City Star.


The humble horsehy is one of the Oldest
and always has been one of the most dis
tinguished of insects He was wor-
shipped by the ancients and placed as a
constellation in the heavens, Tho Philis-
tines sacrificed to Beelzebub as God of
Flies and the Cyreneans to Achor. The
Greeks offered an OK every year to Zeus
Apomyios in honor of the God of Files;
and the Romans sacrificed yearly in the
temple of Heracles Victor, in Rome. The
Syrians too, tried to appease the trouble
some god. The Koran of the Maholne-
tans promised that ''all flies shall perish
except one, and that is the bee fly"
Despite their antiquity flies are still
something of mystery, and it was not
until 1884 that DIR. J. e. Rombout, a
French entoInologist, discovered and ad-
vocated the correct theory Of how house
fly walks on a ceiling. DR.. Rombout
proved that the fly clings to smooth
surface by capillary force, the molecular
action between solid and liquid sub
stances. The insects feet are covered with
many thousands of very fine hairs, each
VI WJllCu CrluluhU6S Ill d UulD.
these hairs runs thin liquid that seeps
through in tiny drop at the end. When
several thousands of thse drops have been
fastened to window pane or ceiling
there Is no difficulty at all for the fly to
hang on, and no difficulty for him to re-
lease himself instan. aneously.
This is the theory CT Rom bout. obtained
after some very fine calculations. A once
popular idea was that the feet of the fly,
n nvIy- \, nd h4r,n thrnr II,
what is called suction to cling to the cell
ing. But Blackwell put flies ia glass
vacuum, where they climbed the sides as
easily as in the open air. Hooke next tried
to prove that the fluid the feet sent out
was viscous and led the insect to the sur.
face like mucilage. This theory was ex-
ploded by Rombout, who proved that the
fluid was not viscous. And il it were,
SAID be, 1T would be absurd to suppose
that fly, after resting in one position
for an hour and giving the thick liquid
time to harden, could release himself in
simultaneously when alarmed.
Then Rombout set about formulating
his own theory. He examined the tracks
of flies on a window pane, and the idea
Of capillary force impressed him. He
dipped the end of hair in oil of olives,
and succeeded in suspending the hair
from clean glass pane. Water brought
the same result as oil Of olives. By So
ries of fine calculations Rombout found
that fly could walk upwa rd on a verti-
cal glass pane supporting an increase over
his own weight@M 900 of q grain. He
then weighted down flies with paper at
tached to their backs, and found by ex-
pertinent that his reckoning was correct.
Rombout, in the course of his expert
ments, discovered other very interesting
things about the fly. Each of the two
wings of the insect is provided with hairs
on the under side that serve as fine
brush to clean the feet. When fly rubs
its legs he is not always washing his
body. but is often removing the dust par
ticles from the hair in his feet that the
nu1d may run better. The feet must be
kept clean or the fly cannot cling to
surface. He finds it impossible to walk
across pane covered with dust. anG oily
surfaces cause the liquid from his feet to
run together. SO that he is apt to slip.
Under the wings of fly is pair of
balancers, little threads that terminate
each in an oval button. When the fly is
on the wing these buttons expand and
guide the flight. A fly has no lungs, but
breathes by spiracles, or breathing pores,
that lie open all over his body and con-
meet with an intricate system of air
tubes. These spiracles are protected from
the dust by networks of fine, fly fbres
that look something like exquisite lace
work
The chief value of the fly lies in his
scavenging qualities. Indeed some scien-
fists say that without his assistance man
would not be able to live in the temperate
zone. The fly feeds on both liquids and
solids. His mouth is shaped something
like pump, and he sips perspiration and
saliva, his favorite foods, through fine
and cunning tubes. Solids he reduces to
liquids before he swallows them by a
process of secretion. He is voracious
eater, and lives largely on the juices of
decaying meat, fruit and vegetables.
Linnaeus, the Swede, asserted that three
flies with their progeny could devour a
dead horse as quickly as lion could.
1t has been estimated by scientists that
fly can multiply himself two hundred
times every twenty hours. Each
new born fly becomes full grown in four
or five days.
Nature has provided well for the fly in
his power OF flight and ability to escape
from danger. He is supplied with seven
thousand separate eyes that never sleep
and can look either in front or behind
Each eye is separate and of peculiar con-
struction, shaped like hexagon. When
alarmed the fly leaps swiftly from his
resting place into the air, detaching his
legs with no apparent difficulty. After
the first bound he is generally out of dan
ger, and resumes his leisurely flight. II
he chooses, however, he can fly twenty