Year: 1875




THE generally-received opinion about
flies is that, despite limitless ingenuity
expended on patent traps and poisoned
paper, they form one of those ills of life
which, it not being possible entirely to
cure, must perforce be endured with as
good grace as may be. Consequently
when they ruin our picture-frames and
ceilings, insinuate themselves into our
milk and molasses pitchers, or lull us to
sleep with their drowsy buzzing, only to
bite us during our slumbers and render
the same uneasy, we thank fate that the
cold weather will rid us of the pest. To
be sure, they are scavengers in their way;
but after we have spent several minutes
in picking a score or more out OF the
butter-dish we arrive at the conclusion
that it is an open question whether they
do not spoil more good material than
they carry off bad.


FestSe0 le1ate, good reader, hasten slow
ly and do not anchor faith to such opin-
ions until you are certain that the above
sum up all of the fy's mission in this
world. Musca d0nest$cG (science uses
six syllables in Latin to express that
which good round Saxon epitomizes in
two) is maligned insect. He fulfills a
purpose of sufficient moment to cause
you to bear his inroads into your morn
ing nap with equanimity, or even CON-
placently to view him congregated by
the score within your hidden sweets.


Did you ever watch a fly who has just
alighted after soaring about the room for
some little time? He goes through
series of operations which remind you
of a cat licking herself after meal, or
of bird pluming its feathers. First,
the hind feet are rubbed together, then
each hind leg is passed over wing, then
the forelegs undergo a like treatment;
and lastly, if you look sharp you will see
the insect carry his proboscis over his
legs and about his body as far as he can
reach. The minute trunk is perfectly
retractile and it terminates in two large
lobes, which you can see spread out
when the insect begins meal on lump
of sugar. Now the rubbing together of
legs and wings may be smoothing oper-
alton; but for what purpose is this
carefully going over the body with the
trunk, especially when that organ is not
fitted for licking, but simply for grasping
and sucking up food?


This query, which perhaps may have
suggested itself to thousands, has re-
Gently for the first time been answered
by Mr.. Emerson, an English chemist;
and certainly, in the light of the revela-
tions of that gentleman's Investigations,
the fly assumes the position of an i'm
portant friend instead of a pest to man
kind. Mr.. Emerson states that he be-
gan his self-appointed task of finding
out whether the house-1y really serves
any appreciable purpose in the scheme
of creation, excepting as an indifferent
scavenger, by capturing fine specimen
and glHing his wings down to micro
scope slide. On placing the slide under
the instrument, to the investigators dis
gust, the fly appeared covered with lice,
causing the offending insect to be
promptly released and another substl-
tuted in his place. Fly No. 2was no better
off than fly No. 1, and as the same might
be predicatedo of flies 3, a, 5 for of nfies, as
the algebras have it), Mr.. Emerson con-
cluded that here was something which
at once required looking into. Why
were the flies lousy? Meanwhile fly No.
2, on the slide, seemed to take his posi-
ton very coolly, and extending his pro-
boscis began to sweep it over his BODY
as if he had just alighted. A glance
through the microscope, however, showed
that the operation was not one OF self
D6dUtllCttlOu, lol WAOlOfOi oiiN ltSS
were. there the trunk went, The lice
were disappearing into the trunk; the
fiy was eating them. Up to this time,
the investigator had treated his specimen
as of the masculine gender; but now he
changes his mind and concludes it to be
female, busily devouring not lice but
her own progeny. The flies then carry
their young about them; and when the
family get too numerous or the mother
too hungry, the offspring are eaten.


Awhile reasoning thus, Mr.. Emerson
picked up scrap of white Writing paper,
from which two flies appeared TO De
busily eating something, and put 1t under
the instrument There were the progeny
again on the paper and easily rubbed OFT
with cloth. "This," he says, set me
thinking. I took the paper into the
kitchen again and waved it around, TAX
ing care that no flies touched it, went
back to the microscope and there found
animalcules, the same as on flies. had
now arrived at something definite; they
were not the progeny of the fly, but anil
malcules floating in the air, and the
quick motions of the flies gathered tnem
On their bodies and the flies then went
into some quiet corner to have their
dainty meal"


The investigator goes on to describe
how he continued the experiment in a