The new era., 1911-05-25

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and that is that they have never been disputed
There is a unanmity of sentiment surrounding the
onslaught on the house fly which ought either
to receive our highest Endorsement or arouse our
darkest suspicion, just the spirit is apt to
incline us.
The house fly proper, Musca domestica. Of the
order of the Diptera, is grayish fly with a mouth
formed for sucking up liquid substances.
1t has a proboscis something like the trunk Of
an elephant in miniature. and it's feet termin
ated each by pair of claws, between which are
more or less membranous arolia or plantulae
which climb polished surfaces. and also pulvil-
1us cushion. 1t does not bite. for that function
is reserved for stable fly which resembles 1t so
closely as to deceive anybody but an entomol-
ogist Neither does 1t die upon the window pane
surrounded by the fungous efforescence SO IA
miliar to the disgusted housewife. That is the
habit of the cluster fly, which is somewhat larger
than the house fly. with darkcolored. smooth
abdomen. and a sluggish disposition.
Several other species bear superficial like
ness to the true house fly and are more or less
mistaken for It, All are inconsiderate in num-
ber in comparison to the common pest. however
that they may safely be disregarded In the dis
cussion.
The great breeding place of the house fly is
horse manure. 1t will, 1t is true. thrive to some
extent in other sorts of decaying animal and vege
table matter, but its partiaty for the stable ref
use is great that the vast proportion OF its on
spring may be considered originating in that
substance.
The fly lays Its eggs upon the manure, which
is its favorite larval flood and generation may
be bred in from ten to fourteen days. according to
the climate. There may be dozen generations
in summer. An individual fly will average 12o
eggs and when the prevalence of horse manure
is taken into consideration. its widespread appl1
cation to farm lands in the way Of fertilizer
its presence in piles in or city stables, Its
upon lawns and suburban gardens the posi-
biities in the propagation Of the fly will be read
fly seen to be past computation 1t is even calcu
lated that single fly, laying 120 eggs, Will pro
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season This probably does not take into con-
liberation accidents which operate greatly to re-
dice the supply.
Some experiments have been made with view
to calculating the number IN which house-fy
larvae In manure but no general average
can be struck. Twelve hundred house flies to the
pound of manure is the result Of one observation
Another showed 200 puparia in less than one cubic
inch. Yet perhaps no larvae can be found IN
the greater part Of manure piles
Because of his habits the house hy is walk
ing arsenal of bacili The old notion that he
valuable a scavenger is untrue He VIII
prey on garbage and carry 1t away as part and
parcel of his tissue but he does not kill the germ
he absorbes. 1t has been proved that the bacteria
not only taken into the fly and pass through
Its body without any loss of their active proper
ties but also that in all probability they multi
ply during their sojourn there.
These germs are deposited upon foodstuffs, and
eating utensils, pass into the human economy IN
spite of ordinary care and If they are OF malev-
olent type and the system which takes them IN
is not strong enough to resist their action, dis
tress disease and death are apt to follow In their
wake. In addition. the fly also disseminates
germs by carrying them upon his body. the cush'
ions of his feet and his wings
Through the researches of w. M. Eaton ana Y.
]. Mason 1t has been found that 1.-The numbers OF
bacteria on a single fly may range all the way
from $50 to 6.6OO,O0O.' No general average can be
struck A few million more or less will make no
difference in the general result
Because Of its prevalence and its familiar asso
ciation with man, Musca domestica has exception
al opportunities to distribute dseasebreeding oac-
teria where they will do the most harm Ger
tain genus of mosquito disseminates malaria. but
the mosquito thrives only in localities especially
favorable to his propagation. There is good rea-