96 
{well, it firft grows yellow, and thence in- 
fenfibly red, and is at length. expanded like a 
bag, or a hollowed Cherry. In the mean 
time, the two edges of this extuberance grow 
fo exactly oppofite to each other on the infide 
of the leaf, and are, as it were, fo united toge- 
ther, that the opening, or chink can fcarce be 
perceived. ‘This is regularly appointed in that 
manner by the Almighty, in the nature of 
things, left the eggs or the young Worms 
fhould fall out of this their cells, or lodgings, 
or fhould creep out before they have attained 
their full perfection, and are become able to fly. 
We have now faid enough of the external 
form of thefe tubercles. 
When we afterwards opened them, we found 
in the infide the following very obfervable cir- 
cumftances : in fome we faw Flies full grown ; 
in others, Worms with fix feet, which were 
real Nymphs of the fecond order ; and alfo 
fome Worms, which, not yet exhibiting the 
limbs of a Nymph, were only in their firft 
growth. We alfo difcovered there a downy 
- white fubftance, and fome tough fluids, which 
feemed to be enclofed in the membrane. 
To treat of each of thefe in their order, I 
fhall firft obferve, that we found the inner fur- 
face of thefe warts more {mooth and flat, than 
the outward. We thought the reafon of this 
- difference was, that in the external furface of 
the warts, the fmaller nerves, which are there 
diftributed thro’ the leaf, were dilated and ex- 
tended with the reft. As to the palenefs of 
the colour, we conceived, that the reafon of it 
confifted in this, that the whole inner furface 
appeared {prinkled, as it were, with meal and 
{mall white grains of bran formed like down. 
From whence this downy matter draws its ori- 
gin, we fhall examine prefently. We fome- 
times obferved fomething, tho’ but little, and 
that not frequently, of a roughnefs in the cavi- 
ties of the warts : but whether the caufe of this 
was, that the old Flies, remaining there for 
fome time, had fcratched the furface with the 
claws on their feet, we could not certainly 
affirm. 
The fmalleft Worms we found within thefe 
warts, were each divided, like perfect Flies, 
into the head, thorax and belly, Tab. XLV. 
Fig. xx11. In the head were feen two eyes 
and two antenne. To the lower part of the 
thorax fix legs were articulated. The reft of 
_ the body was fomewhat fhort. . They appear- 
ed to the naked eye of an azure or fine blue, 
but greenifh under the microfcope. They 
caft a {kin in like manner as the other fpecies 
of Worms. ‘They alfo moved very quick, and 
were much more vigorous than the larger 
Worms, or than thofe that were already 
changed into Flies. 
What deferves moft obfervation in thefe lit- 
tle infeéts, is a heap of flocks or down, which 
each very beautifully and admirably carries ¢ on 
the hinder extremity of its body. Whether 
that down grows out of the very body of the 
infe&t ; which indeed is very likely, or whe- 
ther it be produced from the tubercle or wart, 
2 
“ments. 
The °BXO10 Ke of NOA’ BU OR E; “or, 
and afterwards is lodged in the hinder part of 
the body of the Worm, we could by no means 
difcover ; tho’ we were moft inclined to think, 
that the down grew from the body of the in- 
fect, becaufe we no where faw it {ticking to 
the bodies of the more mature ones, 
In certain Worms, with foft bodies, that live 
expofed to the fun upon the leaves of the Lilies, 
I have obferved, that they heap together all 
their excrements on the hinder-part of their 
body. 
In others that lived among the leaves of 
Thiftles, I have obferved two {tiff briftly hairs 
ftanding in the hinder-part of the body; on 
which was always fixed the fkin which the in- 
fect had caft off, together with fome excre- 
Thus they lie under their fkin, as un- 
der a pent-houfe, free from the fun’s heat, and 
walk up and down with it among the leaves. 
The firft fpecies of thefe Worms, at length, 
changes into a Beetle, of an orange red colour, 
with black horns and legs; but the other into 
a large Tortoife-beetle, in like manner, with 
black legs and a black body. Thefe two very 
extraordinary contrivances do not much differ, 
with refpect to the down, from that which the 
infect, whereof we here treat, carries on the 
hinder part of the body. We may likewife fee 
from hence what miferies all creatures are fub- 
ject to in this vale of filth and calamities, finifh- 
ing their lives continually under unhappines 
and misfortunes. 
The whole inner cavity of the wart, as I 
have already mentioned, is fet as it were, or 
rather {prinkled over, with that farinaceous 
down. And this, doubtlefs proceeds from the 
exuvie, which the infect contained in it has 
' caft off. At the time they cait the fkin and this 
down together, they diffufe it every where 
about by running up and down. This downy 
fubftance is very elegantly divided into branches, 
and greatly refembles that {pecies of nitre which 
rifes out of walls newly built in fome parts of 
Holland: when viewed with a microfcope, it 
feems like the fmaller or branched mofs of trees. 
As to the food of thefe Worms, it is very 
hard to demonftrate what it is: however, it is 
very certain, that they are nourifhed within the 
cavity of their warts. Probably, that white, 
tenacious, and glutinous moifture which I have 
before fhewn to be fecreted within the warts. 
Hence, that humour is fo admirably ordered by 
the all-wife Creator, that it never flows away, 
nor does it wet, nor can it fuffocate thefe little 
creatures. As it is ropyand clammy, the down 
immediately adheres to it, and performs the 
bufinefs of a membrane or bag, in which, as 
in a clofe veffel with a fpout, it lies enclofed, 
and cannot run out of it. 
I compare them to thofe clofe vefiels, be- 
caufe there are fome of thefe bags of that 
figure, Tab. XLV. Fig. xxi11. f. and by means 
of a hollow footftalk, are fixed to the furface of 
the wart, where the humours, juft now de- 
{cribed, probably flows out of that excrefcence. 
Therefore, this is probably the real and only 
ufe the faid down is of to thefe warts, and to 
the 
