‘The JH b 6-1 O.R-Y sof a WS BOG 8: zr 
The Boanih in which thefe Flies lay their eos 3 with an account of the membranes 
they throw off on leaving the Nymphfiate. 
ig appears, at length clearly, by what I have 
obferved concerning thefe infects, how rea- 
dily the females can lay their eggs in the fmall- 
eft cracks of a cheefe ; and I have feen them 
myfelf thruft out their tails for this purpofe, 
to an amazing leneth, and by that method bury 
the eggs in the deepeft cavities. Thefe eggs 
in time produce Worms, which afterwards 
turn to Nymphs, and then to Flies: and this 
bufinefs conftantly proceeds according to the 
immutable decrees of providence, in one uni- 
form circle of production, without the leaft va- 
riation in time or place, unlefs it be when the 
Flies cannot find cheefe to receive their eggs, 
for then they look out for fome other kind of 
food, as much refembling cheefe as poffible, 
in its naturé and qualities. Thus has this {pe- 
cies of little creatures been kept up from the 
time of Adam to our days, thro’ a fucceflion of 
many thoufand generations. 
After having made the obfervations already 
related, I thought it worth my while to exa- 
mine the skin which is fhed by this infect, on 
its appearing abroad in the Fly-ftate ; and up- 
on infpection, I found that it contained a very 
delicate tranfparent membrane thrown off at 
the fame time. In this membrane I could dif- 
cern a. great many of the pulmonary tubes 
which had likewife pecled off from the body ; 
and what was ftill more furprifing, the fnout of 
the Worm, with its teeth or claws, remained en- 
tirely with it. Thefe unfeemly organs, with 
which they heretofore ufed to crumble and take 
in their unfayoury food, and to run about and 
burrow in their putrified habitations, are no 
longer neceffary in the Fly-ftate. Thefe crea 
tures have, inftead of them, a trunk or pro- 
bofcis, by means of which they fuck up the 
fweeteft juices, and a pair of {wift and beauti- 
ful wings, wherewith they ramble at pleafure 
thro’ the untainted air, and raife themfelves 
far out of the reach of ftench and putrefac- 
tion. 
I heartily with you, illuftriotis friend; a fimi- 
lar change and refurrection, of which that now 
we have been confidering, feems to be an 
earneft ; for I am firmly perfuaded; that by 
treading courageoufly to the end of this mor- 
tal life, in the footfteps of our Divine Matter; 
we fhall then change it for a better; and lay 
down this corrupt body, to which we are now 
confined, in order to aflume a far more per- 
fe& one. God, the giver of all good things; 
grant us this necefiary perfeverance, thro’ the 
infinite merits of his only Son, our Lord and 
Saviour. Amen, 
The End of the furprifing biflory of the Acarus, or Mite, and the Fly produced from iti 
The bifory of the Worms found in the tubercles and fwellings of the leaves of 
the Willow. 
Poo Act RoafPe dk 
long to my fourth order of changes, I 
have afligned there the place for all thofe 
Nymphs which are found enclofed in fruits, 
tubercles of plants, trees, and their leaves ; I 
fhall now propofe fome of thofe Nymphs, by 
way ofa particular example. In treating of 
the Worms found in the tubercles of Willow 
leaves, I fhall defcribe the Tubercle itfelf, the 
Ege, the Worm, its Web, the Nymph, and 
the Fly. 
The warts or tubercles of the leaves of the 
Willow, Tab. XLIV. Fig.1. are fo obyious to 
the view, that there would be no neceffity to 
defcribe them, provided each of us had the 
fame ardent defire, ‘and equal curiofity. But as 
all men are not delighted with the fame thing, 
the moft common objects in nature fometimes 
remain unknown, and affect the ignorant with 
a rapturous admiration. For this reafon, I 
-fhall briefly, in this place, explain the con- 
ftrudtion, figure, colour, fituation, bignefs, ten- 
dernefs,; hardnefs, and fmallnefs of thefe tu- 
bercles. 
That the conftruGion of the feveral fwell- 
ings that are obferved in the leaves of the Wil- 
3 
A S in enumerating the Infe@s which be- 
low trees may be diftin@ly known, we muft 
firft confider particularly the leaf itfelf on 
which they arefound. The leaf of the com- 
mon Willow confifts of three coats; the inter 
nal as well as external, are very thin, and are 
fet with light hairs, or a kind of down; but 
the middle coat is nervous and flefhy, if I may 
be allowed the expreffion ; fince the nerves, 
or rather the veffels which conyey.the nutri< 
tious juice to the leaf, are placed in that part. 
Thefe veffels are, indeed, extremely numerous, 
and are divided into fo many fearee vifible 
branches in this coat, that they may be pro- 
perly called the parenchyma, and compared to 
the flefhy fubftances in the vifcera of animals: 
this may be feen moft diftinétly in thofe kinds 
the leaves of which are thick and {pungy. 
The outward coat, or external fide of the 
leaf, I call that part wherein the nerves or 
tibs aré prominent, Tab. XLIV. Fig. 1. a. bes 
yond the reft of the furface:the external or 
outer coat; and the inner coat, or inward fide, 
I call that part of the leaf which exhibits thefe 
nerves, not fo diftinétly confpicuous}4; » Be- 
tween thefe two coats the tubercles of the 
leaves, whereof we are treating, are fituated, 
ang 
