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and this likewife has fome fetaceous hairs, but 
not placed fo regularly. Near thefe appear two 
globules, each of which is fupported by a bent 
or crooked {mall foot or peduncle, and thefe re- 
femble the iron head of a hammer. All the 
little parts, juft now enumerated, ferve for mo- 
dulating the air; for, as this is driven out of the 
thorax into thefe cavities, hence is produced 
that crafhing noife in the fides of the body, made 
by the Fly when it difplays its wings in flying. 
The malleoli, or lithe hammers, in particular, are 
very beautiful, and fuch are found almoft in all 
Flies: but I never faw them in any fpecies of 
Bees; that is, the Bees have four wings: and 
therefore they produce their found or noife ina 
quite different manner. The fame may be alfo ob- 
ferved in Locufts and Grafhoppers. Indeed every 
kind of infect has particular inftruments to vi- 
brate and modulate the air. The part of the 
back oppofite to the abdomen, is adorned with 
a yellow margin; out of which arife two fharp- 
pointed little parts, ike fharp needles, terminated 
by black points. . However, you may more ea- 
fily difcover thefe little parts by the touch than 
by the fight, becaufe they are furrounded with 
a great number of hairs. 
The abdomen, in like manner, confifts of a 
horny or bony fubftance, and being fet all 
round with hairs, has five yellow {pots on each 
fide, which are here and there as if. folded 
up, and laid fmooth, and without hairs. It is 
moreover divided into feveral rings, which are 
difpofed in the fame manner in the male as in 
the female: though, in refpect to the particular 
ftructure, there is fome difference between them, 
as far as they conftitute the Fly’s tail; but this 
difference cannot be feen, unlefs. when thefe 
_ parts are prefled backwards. 
As to the external parts, there is no difference 
between the male and female, except with re- 
gard to the bignefs of the body: the male is a 
full third part lefs than the female, which is like- 
wife the cafe in the Worm alfo, andthe Nymph ; 
for thofe which are to produce males, are lefs 
than thofe which are to yield females. The fe- 
male muft carry in it’ an ovary, which, as it 
contains fo great a number of eggs, that it can- 
not be comprehended in a narrower compafs, 
it is therefore neceflary that fhe fhould have a 
larger body. ‘To make this the more evident, I 
fhall now defcribe the inward parts of the Fly, 
and their difference in the male and female. Let 
it be here obferved, that it is a female I have 
delineated here, and defcribed in general. 
Before I proceed to the internal parts, I mutt 
obferve, that all the Flies which belong to this 
{pecies, do not exactly agree with one another, 
in regard to their fpots, colours and hairs, which 
is alfo the cafe in their Worms ; between which 
there is great difference in regard to their paler 
or fuller colour. 
Now, if, in order to fettle the diffeGtion of 
thefe Flies, you defire to kill them in fucha 
manner as not to hurt any of the parts, there 
is nothing fo proper for this purpole as {pirit of 
wine, in which they die immediately : however, 
I could not entirely kill the Worm in this liquor. 
bi 
Ihave killed a young Fly in the {pace of three 
hours, by the fmell of Brafil tobacco, put neat 
it in a flask: and this indeed I have often done 
fince. 
In the head of a male Fly of this f{pecies, two 
days old, I obferved that little particles of fat be- 
came confiderably fmaller than I before defcribed 
them in the Nymph. When I had afterwards 
removed the cornea from the eyes, the colour 
of the uvea, which ftill lay within that, appeared 
of a bright red. J obferve alfo, that the colour’ 
of the uvea is very different in proportion to the 
age of the Flies: for thofe that have very re- 
cently caft their skin, fometimes fhew the uvea 
of a very beautiful and full orange colour, 
All the mafcles of the legs and wings, which 
are inferted in the horny or bony inveiting coats 
of thefe parts, were in this Fly entirely perfect. 
I found little fat here. But the belly, when 
opened, appeared to be very full of it. ‘This fat 
was of a purple colour, and its particles globular; 
fo that at firft fight I took them foreggs. Thefe 
fat particles very eafily feparate at this time from 
_the pulmonary pipes. Thefe tubes were become 
much lefs, and more contracted, on account of 
the great lofs of the confiderable coats which they 
had caftoff; but Icould not find any tube among 
them dilated into veficles, as is the cafe in many 
other infects. I further obferved alfo, that the 
largeft branches of the pulmonary tubes, which 
I have before defcribed inthe Worm, were here 
inthe Fly compreffed, and infenfibly worn aways 
as it were, or abolifhed: and the fame thing is 
true with ref{pect to the bags, out of which the 
Silkworms {pun their filken threads. 
I obferved alfo two confiderable pneumatic 
bladders of a pear-like fhape; one of which I 
here delineate, Tab, XLVU. Fig. vi. 2, They 
were large, and very much dilated, and were 
fomewhat curled in the curvature of their tops, 
in the manner of thofe little purfes, in which the 
earth Spiders carry their eggs about them: this 
happens probably, becaufe thefe bladders have not 
been extended as much as they might, Each of 
thefe was terminated by a clofer tube, 4, com- 
pofed of orbicular rings; out of the fides of this 
other {mall branches, ¢c, iffued here and there ;. 
two of which I here exhibit magnified. Thefe 
pulmonary tubes are principally conveyed to- 
wards the fides of the body, under the wings, 
and there forming {mall orifices, they afford the 
air by which the Fly makes or produces its noife. 
The ftomach and inteftines were in this Fly 
very much contracted, I found a little air in the 
{tomach, and in its hinder part near the pylorus, 
a brownith yellow fluid. The little inteftine 
found in the other inteftine, was wanting in this 
fubje&, having been wafted away. The four 
convolutions of the four clofed or blind intef 
tines, were here found forced out of the breatt 
into the belly, The rectum fhewed itfelf di- 
lated to a confiderable width, and filled with a 
white moift fubftance like chalk, ! 
Below, in the abdomen, were feen the genital 
parts; the penis, the tefticles, and the feminal 
bladders. The penis is fituated underneath, 
within the laft ring of the abdomen, thro’ which 
ib 
