The Fh 1SeTiO RY. of 1 Nas Gar s:. 
different parts come at once in fight ; thefe are 
a {mall margin very beautifully folded d: the 
end of the inteftinum reGum, or ftraight gut 
é; then the branchiz or gills 4 fome of which 
appear out of the verge in the former figure : 
and at length the uterus g, which I have here 
delineated as diffected and opened together 
with the living foetus contained in it; for the 
young are brought forth alive by this Snail, 
The verge has not a fingular or remarkable 
aperture as in the other land and water Snails, 
but the whole is almoft open on every fide: 
the Snail however knows how to move the 
mufcular parts of the verge, and to fwell them 
out of the fhell in fuch a manner, that by this 
means it draws the air into its cavity ; and this 
air 1s afterwards expelled from thence again, 
when the Snail hides itfelf in its thell. ‘Thus 
imay this {mall complicated margin be very 
eafily feen ; the doublings of winding plaits or 
wrinkles of it arife, in my opinion, from the 
bending and contraction of the body. If this 
little part d be diffected, it appears to be only 
% congeries or heap of tranfparent, chryftalline, 
and equal globules, which are of a ftony na- 
ture, and make a crafhing noife under the 
diffecting knife. The horns, the upper fur- 
face of the mouth, and many other parts of 
this creature become petrified, and therefore 
alfo make a noife like fand, when they are 
chewed a little in the mouth. I mixed {pirit 
of vitriol with them, and it caufed a very ftrong 
fermentation. 
This firft obfervation is, therefore, very 
fingular, and merits particular confideration. 
We fee how the omnipotent God could frame 
a little being, which confifts, as it were, of 
fmall ftones, and yet can move, agitate, con- 
tract, draw in and extend thefe its parts ; be- 
caufe mufcles and their tendons are inferted in 
and runthrough them. But who can defcribe 
how the veins, arteries, and nerves are there 
interwoven and difpofed ? Nobody truly, but 
He alone who made all thefe things. That 
congeries of chryftalline globules, in particu- 
lar, which is fo copious in the horns, that one 
can hardly find: a place wherein the parts 
aforefaid may not be conceived to be fituated ; 
fo that even from thence it appears clearer 
than the light at noon day, what exquifite 
arts and unheard-of miracles the moft fagacious 
Architect has hidden in the immenfe volumes 
of his works. 
If the inteftinum rectum or ftraight gut ¢ in 
this Snail be opened, it is ufually found to be 
full of an earthy gray fubftance, and divided 
on the infide by many membranous and ner- 
vous partitions or inclofures like little valves, 
and grows larger and larger continually, until 
at length it paffes the liver and {mall guts, and 
ends in the ftomach, which feems to be like a 
{mall tube or pipe. The excrements which 
this Snail throws out, are a congeries of oval 
horns, 
vq 
particles, linked or joined together, fuch as 
are found in the inteftines themfelves. 
The parts which I call the branchiz or gills, 
Tab. IX. fig. v. and vi. /, are likewife very won- 
derful ; they are difpofed in a neat order, they 
are of equal length, and are placed at the fides 
of the inteftinum rectum or ftraight gut, which 
they accompany for a great way into the in- 
flexion of the body. If you view them with 
the affiftance of glafles, they refemble a comb 
with broad teeth, though in foftnefs and de- 
licacy they are like little membranes. At firft 
T thought that thefe little parts were mem- 
branous expanfions of the uterus; but from 
their fituation and ftructure I afterwards found 
that they agreed more with branchiz or gills. 
_ The uterus, which, as we have faid, is re- 
prefented, fig. vi. g, open here, is fituated in 
this Snail where the ftraight gut is feen in the 
common covered Snail. When I opened it 
gently, I immediately met under its upper coat, 
which it has in common with the coat of the 
verge, a congeries of oblong little parts, fig. 
vil. @, which were very numerous, and dif- 
fered fomewhat in their length, figure, and 
thicknefs ; and when I removed them from 
theit places, I found they were all alive, and 
were fo many living little Worms, as there 
appeared particles of that fort. On the infide 
of thefe Worms was {een an oblong tran{pa- 
rent afh-gray coloured furrow or ridge. When 
I began to diffect one of thefe Worms, two; 
nay three, and fomietimes four inclofed Worms 
of the fame kind iffued forth * ; having almoft 
the fame figure; that is, a thick head, fig. 
vir. a, and {mall tail 4, like young Frogs or 
Tadpoles. ‘The former Worms indeed moved 
fomewhat flowly, but the latter being put into 
water, fwam very {wiftly, and very ftrongly 
twifted about their little tails. I mutt confefs 
the fight of thefe.aftonifhed me, as I never 
expected to have met fuch, and fo many mi- 
racles in one little creature, or that I fhould 
have been fo well convinced of my own igno- 
rance and blindnefs ina fingle fubject. 
All thefe Worms exhibited a roundith little 
part, tranfparent through the middle of their 
body ; but at the tail appeared fome foft little 
points almoft like hairs. I could not find any 
excrements in them. The little creature itfelf, 
viewed in the fun with a microfcope, feemed 
to confit entirely of {mall grains of fand. 
When I had afterwards taken all thefe parts 
from their places, a new miracle prefented it- 
felf to me: I obferved that the whole tube of 
the uterus likewife confifted of chryftalline 
little ftones, which were as numerous and as 
thick and clofe together, and difpofed in the 
like order as I have before related they were 
about the fkin, the complicated margin and 
Hence I really think that this little 
creature may be properly compared to the co- 
ralline cruft which furrounds hard coral; for 
* The Eels in pafte are in this manner viviparous, and there does not appear to be any diftinétion of fex in refpe& of the 
produce, for all are bearers. 
know, having made the experiments with him. 
The late Mr. Sherwood has given an account of this to the Royal Society, the truth of which I 
x the 
