Memphis daily appeal. [volume] (Memphis, Tenn.) 1847-1886, 1874-11-22

/ greatest disflaence-1g That Ouiy me
| elastic coating Of the tubes is
| incomplete, and that by forcing
air into them by means OF organs IN Tue
| thorax, the tenseness and resistance o.
/ the disc Of the proboscis can be regulat-
Z ed at the will Of the insect as the charac-
! ter Of The food might require. 10 other
words, air here is inside 10 perform the
same office which the blood executes in
the erectile tissue Of the vertebrate ami
mails. The average diameter of the lat
ersl branches Of these tubes, ascertained
hv careful measurements conducted hy
my friend bod, is the one boussndtn
part Of an inch Through the probes.
ems the fly imbibes its food, which OF ne
cessity must be 10 a certain extent
liquid. II the article upon which Il
feeds be dry, as a lump Of sugar or a
crumb Of bread, a species Of saliva is
forced down through the organ and the
dissolved particles are then easily sucked
10. On each side Of the prObOscis is y
labial pslpus. or feeler, by means Of
which the insect is probably enabled 10
gain a more correct idea OF its food and
the surroundings than it could other
wise acquire A little above the inser-
| ton OF the proboscis, and between the
are Thought by some uaturslists to con-
tain apparatus for hearing II time per-
mitted it would be most interesting to
note the wonderful changes Tuug upon
these three organs, the prJboseis, the
Dalpi and the sutennR in different spe-
cies, for 10 one shape .pr another they are
4 common to 3 great number Of insects.
HOW THE FLY SEES.
Take the head Of fiy and with low
magnifying power examine y as an
/ opsQus object. What first strikes the
Observers attention are the two eyes,
| prominent and rounded, one on each
side Of the fore part II the head. These
eyes sre not single like those OF Verte-
( hrale animals, but are c0mpound-made
o., OF thousands OF little six sided eyes,
massed together and imm0yably fixed,
| the whole being covered with a hard,
| horny substance. These little eyes are
| termed ocelh, and their number Is simp-
! iy~amaZiug, amounting ia the head or
tie fy, by careful computation, to about
4 ur thousand. One would think our
! little friend well prepared to see what
might be going on bis sphere OF activity
Objects are, in fact, practically visible
70 such organs Of vision from all dlrec-
iiOls without any need OF turning the
head. This feature OF the compound
eve seems 10 belong specially TO the per
Z feet insect: it Is rarely found in the
/ larva The completely of the fiy's eye
/ is thrown far in The shade by that Of
some other common insects. in
stance 10 the two eyes Of The cabbage
5lftferyiy, there are about seventee thou
sand neeIli, ia the drGQOOH III twenty
] a.. 3
he twenty-five Thousand. AS already
remarked, the compound eye is seldom
| found IN the larv9, never l believe IN
/ the Larvae ofthose insects which undergo
| a eompIrte metamerph0sis-it is devel-
| oDsd at the same time that the wings are
/ evol we'd. ! need hardly remark that
/ the fiy is destitute Of anything like an
! eyelId. The little fellow literally sleeps
! with not oaiy one, but with all bis
! eyes wide open. Que office Of
! the eyeiid. that Of removing from the
organ Of vision particles Of dust which
/ may collect upon its surface, the ny per
! forms very gracefully with lis fore paws.
| Few. Imagine. have been so unob-
J servant SO not 10 have witnessed her al
her toilet assiduCusly engaged IN wash
| ing the face, c0mbing the hair and pol
! is!ing up the eyes preparatory 70 ven
/ tIre "a prOniscuJus society. The ny Is
! furnished with q species OF eyebrows
! caulp9zed OF large and tile hair, which,
/ however, from the position Of the eyes,
I would seem to be more for ornament
! iEau for practical utility. The internal
structure OF the eye is, il possible, even
more striking than the external. Eacu
oaeilus Is 2 perfect lens and forms its
gvu independent image, which is
rsf-rCred upon a fiamenJ Of the optic
nerve. There can be no mixing OF rays,
( and il would seem that, no matter how
mauy Of these independent eyes were
obliteratad, the Others would sull per
| form their fuuctiOns undisiurbeC. IL is
probable. too, that the fly, spite Of the
muItip,icitV Of images conveyed to the
critic nerve. is cOgniZaut Of but Que,
lust a. We, having two eyes, see objects
single.
How THE FLY BREATHEs.
Insects have no lungs Ike the veTte-
b-ate animals, nor giiis like the mol
Iuses. The blood is OxygepiZed by
/ means Of complicated series Of air tubes
ramifving TO the most delicate organs.
We have already seen them in the disk
Of the prObosis where the small e.
branches measure less than the
/ thousandth part Of sn inch IN diameter.
| In the hy these trGehe9, IS the ar tubes
! are called, are easily studied. The air Is
admitted through several breathing
( pores along each side Of the body, and
! thence is distributed to the different or
| cans, going even into the WINS and
] legs. In the thOrsX is pair Of air sacks,
| so arranged as to promote by their con-
| traction or expansion the distribution oil
he air. These sac IS are large IN those
tu.sects capable Of rapid and sustained
a at. small in all others. This arrange
Iii. for the aeration Of the blood does
men, = course, with the necessity OF q
away, o. the comparatively sluggish
heart, ana the blood, necessary fol
o. zion, is conducted by 8
purposes Of muir. NSsels, which OpeI In
OF dorsaI Vt behind, and are
to each other from - vessels con-
closed by valves. The. ~gSrd-the
Tscting, force the blood TO- back
valves closing, and preventing sbiS'
ward flow. The breathing pores, sre
mata, or spirscles, as they are calico, Y
very interesting objects in the fly. Tnt.
are protected at the mouth by the inter- F,
.scing OF an afb0Tescent growth, devel- !
Oped from the marginal integumeut |
The numerous iDsecI-powders, so fatal
10 chiuches, ieas, cockl0ches, and 9th |
ar similar pests, operate in quite me-
5hanical way-either by stopping up at
)ncs the breathing pores, and thus
sUffjcating its victims, or getting into
he trache9, and producing q fatal acute
bronchitis or gallOping consumption.
CONCLUSION.
I come now, in conclusion, TO the
neEest mention of what 70 me is the
most interesting subject Of all, Uiz: that
Of the nervous system. It is a fascinat-
ng heme, and one which brings the ill.,
IuTeT face to face with the
ieepest questions OF biology.
Have in -ects anything winch
CORES pOncs 70 the brain and spinal mar
row OF msn and the vertebrate animals?
la other words, Is our little friend, the
ny, swayed by passions such as love,
bate, anger, and revenge; is memory
present or absent, and what Of The long
train Of sentiments that i'll the teemlng
brain Of human kind? Has the insect
none OF these2 Again, who shall say
that IDsects-the fiy, for instanee-msy
rot possess sense or senses OF which
We are profoundly ignOrant? These, Of
course, are mene questions. III the fly
possess a brain, IN our understanding OF
that organ, Il ia Of the most primitive
and rUdimentary sort, hardly more than
a simple cOmmissure formed by the
junction Of the optic nerves. The insect
Is supplied, however, with a nervous
system the counterpart o. the gangliOnic
or great sympathetic in man and the
vertebrate animals. which for strength
aud endurance almost sgrpasses belief
Cut OF the head Of man, sever the
spinal cord IN the neck of q horse or an
OK, and they die, we may say, instantly.
Decapitate a fly, and, # the operation
be skilltully done, the insect will live
from twelve to tWenty-four hours-per-
haps longer. The power 70 stand erect,
10 walk either upright or back down