The -MIS FOR Y. of PINUS RS, 
up to the head, whéré thus anchored? as it 
were, the reft of its body; which has only very 
{hort feet about the hinder part of the belly. 
In this refpect, therefore, the Worm, ‘of which 
Iam fpeaking, agrees very remarkably with 
the water Worm, from which the Afilus or 
Gadfly proceeds. "The Worm of that Fly car- 
ries its feet, as it were, in its mouth; but I 
cannot pretend to fay the fame thing of the 
boghoufe Worm, as I have not as yet exa- 
mined it fufficiently ; though I think it very 
probable, that its principal feet are fituated in 
that part. The third figure exhibits this Worm 
increafed by the microfcope, to a confiderable 
maenitude. 
N°. V. T exhibit in this place the Worm 
already reprefented under the form it has, after 
lofing all motion, without cafting its ‘kin; 
within which, notwithftanding, it becomes a 
genuine Nymph: and its becoming a Nymph, 
in this manner, muft, [think, be looked upon 
as a fufficient reafon for my giving it this new 
name of the Vermiform-Nymph, fince, at the 
fame time that it retains the appearance of a 
Worm, it really changes, under fuch ap- 
pearance, to a genuine Nymph. This fpecies 
of Nymph, with the Worm’s {kin upon it, in 
the fourth figure, as it appears when magnified 
by a microfcope, and the Nymph itfelf ftripped 
of its fkin, is exhibited in the fifth figure, 
fomewhat larger alfo than nature: but the 
fixth and feventh figures, next following, re- 
prefent it magnified to much larger dimen- 
. fions. 
N°. VI. Exhibits the boghoufe Fly in its 
perfect ftate, as it appears when it has caft its 
two fkins together ; namely, the external hard 
fkin, in-which it had the fhape of a Worm, 
and under which it continued when changed 
to a Nymph; and the internal and more deli- 
cate skin, proper to it asa Nymph; for this in- 
fect throws off both thefe skins at the fame 
‘time. We may obferve here, with what ex- 
traordinary elegance it is cloathed, when the 
time is come for it to appear abroad, and at- 
tend to the great work of propagating its fpe- 
cies! The eighth figure exhibits the Fly, as it 
appears when greatly magnified by the micro- 
fcope. I fhall hereafter explain this figure at 
large, when I come to defcribe the infedt’s ex- 
ternal ornaments. There is, it appears, ‘a re- 
markable difference between this order of 
changes and the firft; as, in the firft, the crea- 
ture iffues perfect from its egg, without paffing 
through any intermediate ftate. This order 
differs alfo from the fecond, as the infedts of 
that order acquire certain membranaceous cafes 
or coverings of the parts within, which rife 
above the reft of the furface of their bodies. 
And, finally, it differs from the third order, 
in which the creatures caft, at different times, 
the skins wherein they appear as Caterpillars, 
and the covering they afterwards wear in the 
form of Nymphs; for, in the fourth order, 
both thefe coats come off together. On the 
other hand, the infects of all thefe orders have 
thus much in common: they are Nymphs un- 
39 
der'all thefe fatés; aiid in every ordet; aid . 
they fo long and fo often change their skins, 
till they are become perfe@t and ready for the 
work’ of generation.. The Nymph, therefore, 
having its. place in all the four orders, is the 
true, the only, and immutable foundation, 
upon which the changes of all thefe infects 
depend, as I have attentively and at large de- 
monitrated in the beginning of this work. I 
make only a curfory mention of it in this place, 
the better to fix’ fo important a truth in the 
memory of my readers. 
Tas. XXXVI Fro:t. 
By this figure, which reprefents the bog» 
houfe Fly’s ege bigger than nature, we obferve 
that it is of an oblong and angular eonftruc~ 
‘tion, fo as to form, in a manner, an elegant, 
chequered, and reticulated reprefentation of 
that kind of cake known in-Holland by the 
name of Woffel. Thefe eges are of a delicate 
whitenefs, and they have two integuments, 
which are. eafily diftinguifhed one from the 
other. The outer integument is the real thell ; 
and this is, in every refpeét, like the fhell of 
a hen’s egg, as appears by its breaking to fmall 
pieces in the fingers. By this means it is an 
eafy matter to feparate this outer cruft from thé 
internal covering, which properly contains the 
embryo of the boghoufe Worm. As thefe 
eggs are moift when juft laid, and are depo- 
fited by the parent Fly upon the walls of bog- 
houfes, and fometimes even in the skins fhed 
by former Nymphs, they ftick together, when 
the air has dried the intervening humidity ; fo 
that, on endeavouring afterwards to feparate 
them, part of the external thell of one egg 
comes off, with the inner fubftance {ticking to 
it. By this means the angular form of the 
latter acquires a kind of proje@ing border. 
This was the cafe with the ege here repre- 
fented, which I thought proper to exhibit in 
that form, in which alone I could procure it 
fingle, on account of its firm cohefion with the 
adjacent eggs, 
lg CLAD NE 
I here reprefent the delicate internal mem- 
brane which covers the egg, as it appears about 
the fore-end of it. This membrane has been 
broken by the boghoufe Worm, when it crept 
out of the ego; fo that we may fee in what 
manner the external eruft or thell has been 
cracked upon this occafioh, and how it has 
crumbled off from the internal membranes: 
It is very furprifing how thefe eggs are covered 
with fo hard a fubftance, refembling plaifter 
of Paris; though it feems probable that Nature 
ordained it fo, the better to thelter the enclofed 
embryo Worm from the putrid and tharp efflu- 
via arifing from boghoufes, in which places it 
is @ften depofited. This led me to an experi- 
ment, by which I have found, that the faline 
acrimony of urine makes fo impreffion upon 
thefe egos. But it is not in boghoufes alone 
thefe eggs are to be found: we meet with them 
in feveral other places, particularly where fruits, 
herbs, and other fucculent vegetables, lie and 
rot, But they appear no where {0 beautifully; 
©YF 
