98 The: BQ OK ‘of 
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NACE UCR Eis son 
Of the footlefs Worm of Cabbage-leaves, which properly belongs to the fourth or- 
der or clafs of natural changes. 
QO N the 15th of Auguft, I found on Cabbage 
leaves feveral footlefs Worms, and fome of 
their Nymphs. The body of the Worms, was 
in the fore part fomewhat pointed, but in the 
hinder part a little thicker, Tab. XLV. Fig. xxv. 
They were alfo divided into annular fegments, 
which appeared in the fkin like fo many fmall 
incifions. They were of a pale green colour ; 
but they appeared variegated, by means of cer- 
tain white vifcera, which were feen through the 
tranfparent fkin. This creature was by nature 
very flow and heavy, though, when touched, 
it fhewed greater agility and fprightlinefs. Whe- 
ther it ufes Cabbage leaves for food, or hunts 
there after fome green little fix-footed infects, 
which are at length changed into Nymphs of the 
fecond order, and from the latter into Flies; I 
have not accurately inveftigated: I know fome 
ate of this laft opinion. This Worm ufually 
firetches aloft the fore part of its body, in the fame 
manner as an Elephant does its trunk, when it 
firft begins to move and go forward. ‘Therefore, 
I do not doubt, but it is the very creature which 
Goedaert defcribed, Exper. XI. part 11. 
When this Worm hath at length fed enough, | 
and its internal parts have acquired fufficient 
ftrength to put on the form of a Nymph, it is 
then changed, Tab. XLV. Fig. xxvir. and 
XXVIII. into a real Nymph of the fourth or- 
der; which change is performed in the follow- 
ing manner: We firft obferve, that the Worm, 
before it cafts any fkin, becomes infenfibly fhor- 
ter; that its head is entirely contracted on the in- 
fide, and at the fame time it becomes thicker ; 
but the hinder part, by degrees, grows {maller, 
and more flender, the body thus lofes its former 
fieure. For the blood, and all the fluids, are 
propelled forward to the new parts, which are 
now increafed, and {wollen under the Worm’s 
uncaft fkin, and appear divided into the head, 
eyes, thorax, legs, wings, and body: this may 
be clearly feen, if this Nymph be artificial- 
ly ftript of its yet uncaft fkin. One may like- 
wife fee the feveral particulars beforementioned 
through the fkin itfelf; when the Nymph, be- 
ing fome days old, begins to acquire its proper 
colours. 
As the colour of the Nymph, on the change 
is white, and is afterwards altered into a green, - 
mixed with a pellucid white; the red eyes in the 
head appear, Fig. xxviri.@a, gradually through 
the tranfparent fkin, ‘The fame thing holds, 4, 
in regard to the thorax, which exhibits fome 
pellucid hairs on its furface. In the hinder part of 
the body, the abdomen is feen through the {kin, 
divided cece into feveral rings, which are like- 
wife fet with {mall hairs. On one fide of the body 
is feen a wing d fomewhat pellucid, ‘Towards 
the hinder parts, and near the taila curled little 
veflel, Tab. XLV. Fig. xxvii. e, which indeed 
feemed to me to be a pulmonary tube rolled 
out. 
.thereof, which I have given here. 
When this Nymph is grown older, and at 
length becomes all coloured, then thefe parts 
appear moft diftinctly, if the {kin be taken off: 
this will be evident from the magnified figure 
In this are 
difcovered, Fig. xxix. a, the Nymph’s reticulated 
eyes; above and between which are two fhort 6 
horns. The probofcis or trunk is laid along the 
breait ¢, and near it, the firft and fecond pair of 
the fore legs, are feen to be beautifully difpofed. 
On each fide of the breaft lie the folded wings, 
dd, and under them the laft pair of legs, e. 
What deferved the greateft notice in this creature 
was, that the extremities of the genital parts, 
were placed, /7, as it were, beyond the rings 
of the body, and terminated in fhaggy points: 
which are at length drawn into the body, when 
the Nymph puts on the form of a Fly. 
This Nymph is therefore a very uncommon 
one; and though properly referred to the fourth 
order, yet it undergoes confiderable changes, 
and exhibits no more of its former fhape than the 
fkin only, which it does not caft, but retains. 
The reafon why this Nymph fo much differs 
from others, of the fame order is, becaufe it is 
invefted with a tender and thin fkin, which ob- 
fequioufly accommodates itfelf to the growing 
and protuberant limbs within. 
explained in the preceding pages, where I treated 
exprefly of the nature of the fourth order. We 
muft further obferve, that this Worm, when 
changing, is not difengaged from the Cabbage 
leaf, as is the cafe in regard to many other 
infects: on the contrary, it fr glues itfelf thereto 
by a vifcous matter, which appears Fig. xxvitr. 
Sf, like a thin membrane on the leaf. 
The Worm having had this form fixteen or 
feventeen days, the hidden Nymph then breaks 
open, and cafts off the outward fkin, and at the 
fame time draws a thin film off from the whole 
body, and from all the limbs, which is left on 
the infide in the old fkin. ‘Thus the Nymph ap- 
pears, Fig.xxx. at length under the form of a 
Fly. The young Fly is much fimaller at firft, 
than in a quarter of an hour afterwards ; for its 
parts are in that time infenfibly extended, parti- 
cularly about the head and belly, fo that the Fly 
becomes almoft twice as large, in fo fhort a time 
after it is produced; after which it never in- 
creafes any more. If any one would know the rea- 
fon how the body of this Fly is fo remarkably 
diftended, it will appear, on examination, that 
it confifts in refpiration, which fills all the pul- 
monary tubes, and pneumatic bladders with 
air; and thefe, on the other hand, expand the 
hitherto foft body of the creature, and give it a 
firm and durable figure. 
This Fly is beautifully divided into the head, 
thorax and abdomen, and has fix legs and two 
wings. Behind thefe, two little parts are obferved 
‘to be fixed to the thorax, fupported, as it were, 
by two fine footftalks, with their extremities 
. headed ; 
All this I have . 
