El Paso herald. (El Paso, Tex.) 1901-1931, 1911-04-22

]
strainer, allowing only very small par
ticles to pass. The whole affair, togeth
! er with the oesophagus, is modified TO
/ sucking.
Flies Have Large Eyes.
| Nearly the whole front OF fly-s heaC
! is occupied by two huge ewes, each o
/ which is in reality several thousand eve.
in one. Each of these thousands Q.
, eyes has its own lens-implying. Of
course, a separate image of any object
seen. But, necessarily, all of these mul-
titudinous lenses operate together IL
! such way that only a single object
Is seen by the insect-iust as we with
our two eyes, see only one object 1t is
very wonderful and elaborate visual
contrivance, and. in view of its size
and complexity, one is at no loss to
understand why the fly is able to see so
well as it evidently does.
In order to find out how things look
to a fly, Dr. Cobb took the trouble TO
test this matter by an ingenious method
OF his own. Having killed a fly, ne
carefully cut away the outer layer of
one of its great eyes, thus obtaining a
thln convex plate, comprising a multi
tude of tiny facets. each containing a
lens. The back of this he cleaned with
a soft brush, and then mounted it on a
piece OF glass in such a way that the
outer, or convex, surface was away from
the glass.
Having thus provided himself with a
multiple lens at the fly's expense. he
proceeded to take photographs of various
objects through it, employing for the
purpose a camera connected with a mi
croscope. The camera was made to take
the place of the human eve looking
through a microscope. and showed Just
what man would see if he were able
to look through the eve of a fly.
Can See Well.
As a result. it was found that each
facet of the fly's eve carries a lens of
practically universal, fOeus-goOd, that
IS to say, for all distances But the
most remarkable fact ascertained was
that the insect is able to see things with
utmost distinctness at an extraordinary
near point. Objects only half a MILL
meter away from the fly lenses-not
much further than the thickness of a
sheet of note per-were SHARPLY in fo-
Gus. Also it became apparent that the
fly could see with clearness objects so
small as to be to us invisible In other
words, it would seem that the eve of
TINS insec+ possesses a microscopic Wis
ION OF far power.
One of the most noteworthy things to
be mentioned in this connection, how
ever, is the fact that on the top of its
head. between the two great ewes al
ready described, the fly has three little
bits of eyes feall them "eye- kins." for
lack of a better name), situated in
group all by themselves. 1t is not
known with certainty what they are
meant for; but, inasmuch as they must
have some purpose, it is srrmised with
a certain amount of seeming confirma-
ton from the character of their struc-
ture) that they are intended for very
distant vision. If this idea be correct, |
the house fly IS provided with tele-
scope, as well as microscopic facilities, I
rendering the creature. in all matters |
pertaining to vision, incomparably su-
perior to us human beings.
House Fly Has a Voice.
How many people are there who have !
noticed that the house fly possesses a |
voice? It's buzz is different matter. |
being caused by the rapid vibration of I
The insects wings. But, if one catches (
| fly on a window pane. one win some /
lines here 1t cr-- Out-a verv fine note
II high pitch, quite distinguishable /
rom any other sound. The same note
vail occasionally be audible. to asensi-
I've ear, when one fly is chasing another
ID nut a room
As for the buzz, ire wing beats which
lroduce it vary in lumber with different
lies, but commonly run up to 800 or
100 to the second. 1t is a phenomenon
20 remarkable as to raise an entirely
new mechanical question. Some hum
ming birds flap their wings at maxi
mum rate of 10 times a. second. But
hink what 300 or 400 vibrations signi-
Y!
The humming bird whose wing vibra-
ions far exceed in rapidity those of any
,ther feathered creature, is provided for
he purpose with very powerful muscles.