The BO O'-K of 
depreffions of the skin are ftill plainly confpi- 
cuous. Nay, on the hinder part z, where the 
skin is twifted and complicated, whoever accu- 
rately examines the skin itfelf, may {till ob- 
ferve the coat that was caft by the intefti- 
num rectum. It is likewife remarkable, that 
the skull remains fixed to this caft skin of the 
Coffus; whereas the contrary happens in Silk- 
worms, whofe skull always feparates from the 
caft skin, except under the laft change, when 
the Silk-worm is changed into an Aurelia or 
Chryfalis. The head and teeth of the Coffus, 
having lately caft their skin, grow white and 
become flexible and tender, though they are 
1306 
LON aod on Li a 
NATURE;a, 
otherwife hard as horn, nay, as bone; info- 
much that when the Worm is provoked, it 
attempts to bite even iron. But what. effect 
this change of the skin in the pulmonary pipes 
at length has in the Worm, will afterwards . 
appear, when I fhall at the fame time thew 
more clearly, that there are more than eigh- 
teen principal branches of pulmonary pipes in 
the Coffus, as is likewife the cafe in Silk- 
worms. ‘This may be likewife exemplified in 
the Worm of the Hornet, which has twenty 
points of refpiration. But I {hall now proceed 
to the anatomy of the Coflus. 
ware ilh 
The anatomy of the Coffus. The manner in which it is to be killed. Its blood, 
heart, fat, pulmonary tubes, throat, flomach, {pinal marrow, and the nervous 
recurrens. Whether the Coffus is eatable. How it may be feafoned or pre- 
Served, with fome uncommon obfervations. , 
I H AVE various contrivances to execute 
the diffection of the Coffus, according to the 
different ends I propofed to myfelf in each dif- 
feftion; but that which I ufe moft frequently 
for this purpofe, is to kill the Worm in {pirit 
of wine, or to fuffocate it in rain water fome- 
what more than lukewarm : after fome hours 
I take it out again, and thus it not only lofes 
all its motions, but its mufcular fibres are never 
afterwards contracted, which would otherwife 
very much incommode the difleétion. 
When the skin is opened along the back, 
where the heart is placed, which is extended 
through the whole back, in form of an oblong 
canal, and appears about the loweft rings in the 
manner of lymphatic veflels; immediately after 
the blood, which is a watry humour or ichor, 
iffues out at the wound, the moving fibres 
of the annuli or rings, Tab. XVII. fig. vit. 
come then in fight. Thefe are indeed very 
wonderful to obferve, and can fcarce be well 
defcribed, for they fhoot over each other, from 
one ring to another, in a ftraight, tranfverfe, ob- 
lique or decuffated direction, and often join one 
another as by inofculation. Some of them are 
longer, fome thicker, and fome fmaller than 
others, as I have endeavoured to reprefent in 
fome degree in the figure juft now cited. But 
the mufcles are not fo beautiful in any of the 
infect kind as in Snails, as may be feen in their 
hiftory, and the figures illuftrating it. 
All along the courfe of the heart in the 
Coffus, fimilar moving fibres are likewife placed, 
which are inferted into the heart itfelf; and 
they, like fo many different little ropes, expand 
and contract it. The external furface of the 
heart refembles a membranous oblong: tube, 
fig. vil1. @, which is very narrow 4 about the 
top, and is likewife contracted like a knot about 
the middle of the body, and widens againc, 
and at laft is joined d very clofely in the hinder 
part under the thirteenth ring. On each fide 
of the heart are feen fome blackifh uneven 
points or {pots, which render the heart, though 
tran{parent enough of itfelf, the more diftinétly 
con{picuous. 
If the incifion be afterwards made fomewhat 
wider, the fat appears, confifting of innume+ 
rable, very {mall, and as it were fandy, fig. rx. 
globules, which, when viewed with a microf- 
cope, feem to be again compofed of innume- 
rable and yet fmaller particles, all which are 
fupported by very thin and tranfparent mem- _ 
branes or coats, fig. x. aa, which are varioufly 
diftributed through the body of the Worm, 
and with their nu:.iber and diverfity very much 
obftrué the fight of the internal parts. If this 
fat be viewed with a microfcope, the pulmo- 
nary pipes 6 4 appear to run up and down 
through it, and the fat itfelf is exhibited in 
form of minute, oily, globular particles cc, fwim- 
ming between white, {pherical, and membra- 
naceous parts. But when the fat of the Coffus is 
received into a {mall glafs, and placed on a 
burning coal, {till covered with its afhes, then 
in roafting there iffues out of it an oily white 
fubftance in great abundance, which being put on 
paper has the fame effect that oil has, and when 
thrown into the fire it burns very bright; and 
therefore from all thefe figns, I conclude it is 
of the true nature of fat. This fat is not of 
a regular but various figure in its difpofition, like 
certain. pneumatic veficles, which I {hall here- 
after delineate in the fheaths or cafes of the 
wings. ‘This, however, is to be underftood 
only in refpect to the divifion of thefe tran{pa- 
rent coats, whereby, as a foundation, the fat 
is {upported, for the figure of the particles of 
the fat itfelf is commonly fpherical. In the 
Silk-worms, whofe fat is yellow, it appears of 
a very 
