The aE) SUT TOVRMY Got ai NS @ Gane. 
Worm might be fuppofed to have infinuated 
itfelf into their fubftance. Some of the Worms 
within thefe coats were dead, which I attri- 
buted to the firiking of the leaves againft one 
another with the wind; or to their withering 
and wrinkling up, for want of nourifhment ; 
or, finally, on account of other external inju- 
ries. As yet I have had no opportunity of 
Te IR: D “Oskes 
| Qs the 21 of Auguft I found, within the 
fame coats of certain Alder-leaves, a third 
fpecies of Worms which had no feet, and were 
divided into twelve rings. This fpecies had a 
much rounder body, Tab. XLIV. Fig. xvitt. e, 
than the firft, with a very {mall head and teeth. 
The back and belly were diyerfified with va- 
rious white fpots, which appeared through a 
yellowifh green tranfparent fubftance, and 
feemed to me to be fo many particles of fat. 
The neft which this Worm had gnawed itfelf 
within the coats of the leaf, was not fo fpacious 
as thofe of the two Worms laft treated of ; and 
fometimes one neft contained two Worms, 
which lived and fed together in common; but 
in this cafe, the neft was fomewhat larger. In 
another leaf I found two of thefe Worms, 
* that had each formed itfelf an oblong web, f- 
In the fame place I alfo found their excrements, 
and the fkins they had caft off. 
Thefe webs were red, as were alfo the 
fhrivelled coats of the leaf that contained 
them. On opening one of thefe webs, in 
hopes of finding a Nymph, I met with a 
Worm, which as yet had fuffered no change, 
except that of being grown a great deal fmaller 
89 
tracing this infect through its changes, fo that 
I have nothing more to fay here concerning it, 
but that it was very delicate, and moved itfelf 
but weakly. On taking it from within the 
leaves, it died in 4 day or two. The Alder is 
not the only tree inhabited by thefe Worms: 
they are to be found alfo on the Pear and 
‘Apple, and many other kinds. 
eRe Aa ele. NG 
than before; and it was impoffible it fhould 
not have loft fomewhat of its bulk, confider- 
ing the great quantity of filk it had drawn 
from its body, to form itfelf a covering. Four 
wecks after this, I opened another web, little 
thinking that I fhould meet with a fecond dif- 
appointment, yet fo it happened; for there was 
no Nymph even yet, but only the Worm lay 
there quite unaltered. I have therefore laid 
by fome of thefe webs, in order to difcover 
next year, if poflible, what kind of an infe& 
they produce, which is poffeffed of the fur- 
prifing art or power, as a faculty of burying 
its eggs thus fubtilely within the two coats of 
leaves. When thefe. Worms are very {mall, 
their nefts, which they gnaw themfelves, are 
very {mall likewife, Tab. XLIV. Fig. xviit. g; 
but they widen proportionably by degrees, 2, 
as their inhabitants grow bigger and bigger. 
From whence I conclude, that the holes in 
which they have been originally depofited, in 
form of eggs, muft have been of a minutenefs 
almoft beyond conception. But, as yet, I have 
no experiments or obfervations to enable me to 
fay any thing certain on this head, 
The fame fubjeét continued.  Ehiftories of infeéts that are found in fruits, tubercles 
or warts, and leaves of plants. 
ing in the fields of Folland. 
Waite about the middle of fummer into 
the country, in order to find leaves for 
Caterpillars I was at that time feeding, I hap- 
pened to obferve on a common Thiftle, not as 
yet arrived at its full growth, a yellowith flen- 
der Fly, Tab. XLV. Fig. 1. a, with a large 
head, red eyes, two fhort antenne, and wings 
very elegantly coloured. ‘This infect had thrutft 
out, toa very great length, the extremity of 
its uterus or womb; and was employed in en- 
deavouring to bore, by means: of this part, a 
hole into the fubftance of the leaves, wherein 
it might depofit its eggs. This curious fight 
could not fail of engaging my attention, and 
accordingly I {pent a long time in viewing it, 
equally aftonithed at its novelty, and overjoyed 
at having an ‘opportunity of feeing, with my 
own eyes, the manner in which this kind of 
An obfervation on the common Thiftle grow- 
infects attack the plants; which are proper to 
afford their Worm-offspring a never-failing 
food and fhelter: as likewife to obferve their 
method of conveying into thefe plants the eggs 
from which their Worms are to proceed. In 
that part of the plant where thefe eggs have 
been depofited, there afterwards grows a large 
globus, or round tumour, in fubftance not un- 
like the calix or cup of the Hazel-nut, which 
by degrees becomes ligneous, and hardens to 
a more compact fubftance, refembling wood, 
‘Within thefe {wellings there appear, here and 
there, certain white Worms, which change 
firft to Nymphs, and then to Flies. Some 
pretend this Worm, carried in a purfe, along 
with its tubercle or fwelling, is good againtt 
the piles. 
Of 
