The 
éach from the reft, without the help of particular 
fisures, There is one thing remarkable in fuch 
Nymphs, which is, that we may eafily obtain 
a full and fatisfactory view of their change from 
the Worm to this ftate, and of the admirable or- 
der obferved by nature, in affeCting this tranf- 
mutation, fo as to trace with our eyes the mu- 
tation hitherto confidered as a metamorphofis of 
the creature, from a Worm'to a flying Infect. 
Icannot therefore fufficiently wonder, that noné 
of the authors, whofe works I have read, have 
taken any notice of the Worms now under our 
confideration, or given us any drawings of the 
Nymphs of fuch Worms. Goedaert, it is true, 
was acquainted with the Flies, to which they at 
laft change, and has given us pretty good figures 
of them. To defcribe thefe Flies ina few words, 
I need only remark, that I have already taken 
 f{ufficient notice of them under the name of the 
Pfeudo-{phece in the detail of my third order, 
to which they properly belong: in that place too, 
dT obferved, that Goedaert’s devourer or deftroyer 
of Spiders, fhould be looked upon as a Fly of 
the fame tribe. 
I fhall now deliver the method of viewing 
thefe moft fingular and interefting changes. Care 
muft be taken to obferve when the Chryfallides 
harden, and change colour ; juft at that time they 
are to be broke open, and the enclofed Worm 
taken. out, and put into a little box, where you 
may very diftinctly and confpicuoufly behold its 
gradual change toa Nymph, and from a Nymph 
toaFly. 1 fhall, at another time, with God’s 
permiffion, and with a view of promoting the 
glory of the wife and powerful Creator, endea- 
vour to fet in the cleareft light, among my {elec 
obfervations, the manner of fuch mutation; and 
likewife to fhew what a great quantity of excre- 
ments this Worm voids in the mean while; and 
how it fometimes is obliged to fpin a web, with 
many other particulars very well worth the at- 
tention of the curious. At prefent, I have not 
oppportunity to dwell any longer upon this fubject. 
In the thirteenth place, I count of this order 
thofe Nymphs which become fuch, and after- 
wards Flies, from fifty to two hundred together, 
in the fame manner with the Nymphs laft men- 
tioned, within the body, or skin of a fingle 
Chryfalis, and proceed originally from a great 
number of little Worms that have preyed upon 
this Chryfalis. Thefe Flies alfo were known to 
Goedaert, though he was altogether ignorant of 
the true manner of their generation, or the real 
nature of the Nymph, by which alone thefe hi- 
therto fo perplexing appearances can be folved. 
Nor fhould I have fucceeded any better than thofe 
who have gone before me in this province of 
Natural Hiftory, had I not, purfuant to the 
advice of the immortal Harvey, called anatomy 
to my afliftance, upon every occafion, and la- 
boured with infuperable patience to difcover, and 
diftin@tly comprehend, the true principles of thofe 
HISTORY 
ofl IONOSE, GTS, 37 
furprifing changes, as often as there was a pofii- 
bility of difcovering and comprehending them. 
Without experiments, we cannot expect any 
clear and certain knowledge in matters of this 
kind, whether our conclufions are drawn imme- 
diately from our own reafonings concerning the 
things before us, or from inductions built upon 
their refemblance to others, we are equally liable 
to go aftray, and miftake the produCtions of our 
own imagination for the reprefentations of nature, - 
as fubfequent experiments generally prove. Def- 
cartes therefore had great reafon to fay, that he 
fet more value upon the folid experiments of me- 
chanicks, than the barren and fine-fpun contem- 
plations of philofophers. The creatures juft 
taken notice of, as appearing in great numbers 
within the fkin or body of a fingle Chryfalis, 
may be traced through all their mutations, in the 
fame manner with thofe that require each of 
them an intire Chryfalis for this purpofe ; and 
certainly a favourable opportunity of viewing, 
though but once, fo great a miracle in the works 
of nature, muft afford the higheft pleafure to 
thofé who are defirous of being acquainted with 
fuch wonders: but now they may eafily pro- 
cure themfelves this fatisfa€tion, as I have, I 
flatter myfelf, removed, though not without great 
pains, the many obftacles which hitherto op- 
pofed their defires. 
I place alfo in the fourth order, thofe genuine 
Nymphs, which become fuch from Worms of 
a particular kind, found within the bodies of 
larger Vermiform Nymphs, in the fame mannet 
with the Worms of the firft mode of the third or- 
der, This I had an opportunity of obferving inthe 
Vermiform Nymph of the common Fly of our 
neceflary-houfes ; and the fame is to be obferved 
alfo in the infects of the firft order. 
In the fourteenth place, I muft add alfo to 
this order, all thofe genuine Nymphs which we 
find in the middle of fruit, in the warts of 
fhrubs *, and the leaves of plants, in rotten parts 
of wood, and in other ob{cure and fecret places. 
T have collected fome of thefe Nymphs, and the 
Plies into which they change; asalfo the feveral 
fubftances in which the worms are found; all 
which the curious are welcome to examine, that 
the adorable Author of fuch wonders may re- 
ceive an additional tribute of praife and glory. 
I preferve likewife fome of thofe Flies which 
proceed from the lithe Worm, that Redi found 
within the excrefcencies of willows, without be- 
ing ever able to difcover their changes. On open-= 
ing the bodies of thefe Flies, we meet with eggs, 
which perfectly refemble thofe found in the fame 
excrefcences ; from whence, as well as from 
many other obfervations, we may fairly conclade, 
that all the Worms found in vegetable fubftances, 
are originally depofited there by the parent in- 
fects in the form of eggs. For a particolar il- 
luftration of thefe things, I muft refer to the 
explanations of the XLIV. and XLV. Tables, 
* Thefe all owe their origin to eggs of Flies, and principally to the feveral fpecies of Ichneumon-fly, which this author calls Pfendo- 
fphece. 
All infe&is are directed by inftin@ to depofit their eggs where the young will find food. Butterflies do this on the farfaces 
of leaves. ‘Thefe Flies lodge them in the fubflance. They have for this purpofe a hard and fharp inftrument at the hinder part of 
the body, and with this they bore ahole in the leaf or rind, and la 
mal, alter the courfe of the fibres, and hence arife galls on the oak 
upon the Dogrofe, and innumerable other vegetable excrefcences. 
y their eggs. The wound and juices thrown into it by the aniy 
3 in each of which, there always ig a worm originally, the burrs 
In 
