The HISTORY of INSECTS, 95 
Of certain Worms that feed within the [pongy excrefcence of the Dog-rofe. 
‘T HE excrefcence of the Dog-rofe, as to its 
external appearance, is not altogether un- 
like that of the Oak reprefented in Fig. v1. of 
this plate, though it is not of a woolly, but on 
the contrary, of a fpungy fubftance, in fo much 
‘that it may, with great propriety, be called the 
{fpunge of this fhrab. The colour, when dried, 
is a blackifh gray; and in the fame flate, the 
furface of it is full of little cavities and prominen- 
cies, Fig. 1x. aa. It grows as the other, at the 
extremities of the branches, where it ftands 
upon the center, juft as the bud of the Rofe 
does upon its ftalk 6. On opening this ex- 
crefcence, we find in it a great many cells, 
Fig. x.c, full of little white Worms of diffe- 
rent fizes and ages. Thefe Worms aflume, 
by degrees, the Nymph-form, in the fame 
manner with all the Worms living in excref- 
cences, that I have hitherto mentioned; and 
under this form they moft manifeftly exhibit 
the limbs of the future Fly: this happens 
about the end of fummer. 
I had the -pleafure of obferving two fpecies 
of Flies iffue out of thefe fpunges; thro’ holes 
they had made in them for that purpofe. The 
firft f{pecies was not.unlike the Flies that had 
been produced, at my houfe, from. the tuber- 
cles of the Oak, only, that they had fomewhat 
thicker bodies, Tab. XLV. Fig. .x1..d, with 
black eyes, and all the reft of them: was of a 
redifh brown colour. The other {pecies e were 
of the Bifeteus kind, or had two-hairs at the 
tail, though this character was peculiar to the 
males. They had likewife, in common with 
the firft f{pecies, four wings and fix red legs. 
Their. bodies were oblong ; and their heads, 
which hung to the thorax by a. very flender 
neck, were furnifhed with a pair of redith eyes. 
Their bodies all over fhone like thofe of the 
Cantharides, or Spanith Flies, with a gilded 
green, fo as to afford a very entertaining {pec- 
tacle. ‘Thefe Flies. did not all appear abroad 
at the fame time, but were employed for feve- 
ral days fucceflively in making themfelves open- 
ings in their habitations : this they effected by 
gnawing the {pungy fubftance with their teeth, 
into a great variety of holes and cavities, F ig. 
Ixia fe 
Al careful and exa& obfervation which I made on the tenth of Fuly, 1674, on the 
black Poplar, in prefence of the principal magiftrate of Nieuwenrode, and bis 
lady ; both very curious in examining the natural wonders of the creation, 
. L THOUGH all the works of the Almighty 
are wonderful, we may obferve, that fome 
publith his praifes more manifeftly than others. 
This appears moft eminently in the various or- 
ans of generations beftowed upon animals, 
and the different manner in’ which they ufe 
them ; for fome declare, by evident and intel- 
ligible characters, the power and contrivance 
of the great Architect, whereas others repre- 
fent it by marks that are fomewhat obfcure 
and myfterious. 
On the tenth of July, 1674, as we wete go- 
ing in a chariot to Scheveling, we faw fome red 
fruit like Cherries hanging from the leaves of 
the Poplar-tree, in fuch numbers, that they 
could not but ftrike the eyes of all that ‘paffed 
by. When we viewed them near, it appeared 
to us, that they were fo many rough tuber- 
cles, or extuberances, on the leaves ‘of thofe 
trees, Tab. XLV. Fig. xxi. a, each of which, 
when opened, fhewed a great number of living 
infects, to the amount of 60 or 70. Thofe 
warts, or protuberances, which projeCted above 
the furface of the external coat of the leaves, 
were fituated exactly under the middle of the 
nerves or ribs; fo that thefe nerves paffed 4 over 
them ; being fometimes a little higher, and 
fometimres lower, according as the warts them- 
felves projected, more or lefs, without any or- 
der from the leaf. Two warts were likewife 
fometimes found, but very feldom, on the 
fame leaf, Their fize greatly differed; fome 
of them, as if young, were fmaller; others larger 
and more fwollen; a third kind alfo crew ftill 
larger and higher than all the others. When 
we firft faw ‘thefe tubercles, we thought they 
were every way fhut up or inclofed: but upon 
amore accurate examination, we found, that 
each of them had, on the infide of the lear, 
where they were fmooth, an orifice ¢ fome- 
what long, thro’ which the ina pafied at 
pleafure. 
It is worth notice, that the leaf always {welled 
under its largeft nerve, which it conftantly ele- 
vated ; and likewife, that this tumor was only 
found about the nerve, and in the middle of 
the leaf. The reafon of thefe circumftances 
feemed to us to confift in this; that the egos 
of the infect-inhabitants had been imprefled on 
that place only, and that the nutritious juice of 
the leaf was for the moft part conveyed thi- 
ther. ‘Thus it might eafily happen, that the 
leaf might be ‘there increafed and inflated by 
the nutritious juice accumulated by the irrita- 
tion which had been produced by the lodging 
Of the eggs in the fubftance. And hence alfo 
‘we obferved plainly, that the whole wart on 
the leaf was nothing elf but a larger dilatation 
and éxpanfion of the leaf itfelf; which caufed 
the nerve, puthed out at the fame time, to be 
twifted into various bendings and windings 
which were vety confiderable din‘ fome of 
them. 
It deferved’ great confideration to. obferve 
how regularly all thefe things are.done. For 
when the leaf is newly ftruck and begins to 
{well, 
