é 
Phe. Fels F OR ¥ 
Thefe Worms are, on their fore part, pretty 
like Lumbrici terreftres, or common Earth- 
worms, but on their hinder part they are fome- 
what thicker, and they generally lie in plaits 
and folds within the lungs. In fize they differ 
but little from the Worm that gnaws or cor- 
rodes the fhell of the common Wilk. Their 
colour is a yellowifh white, except that they 
are black towards the tail, which variety in co- 
lour proceeds from that of the food they have 
taken into their bodies. They have their 
mouths conftantly fixed to the internal mem- 
branes of the lungs, from which they fuck the 
blood. On feparating them cautioully from 
thefe membranes, we may difcover in the mem- 
branes a little opening made by thefe infects, and 
even a {mall quantity of blood difcharged from 
that aperture : the mouth alfo of the piratical 
Worm appears bloody, if immediately in- 
fpected. “Thefe Worms appear to have an- 
other aperture in their breaft, which however 
I did not fufficiently examine. I omitted alfo 
taking a furvey of their infide, except that I 
obferved fome great and {mall guts, and fome 
diftinét particles; but the infect’s fkin being 
tranfparent, thefe particulars could be feen 
without diffection. 
Other kinds of Worms are often found alfo 
in the lungs of Frogs. Thefe are like briftles, 
with fharp heads and tails, and they coil them- 
felves up. In colour they differ little from the 
firft kind, only that on the infide of their bo- 
dies they fhew thro’ their tran{parent fkins, 
fome of their inteftines in the form of a little 
thread or line of a dufky brown. On opening 
both thefe fpecies of Worms, immediately ta- 
ken from the Frog, I found in them a great 
number of {mall particles wrapped up in an 
oblong membrane. On obferving that thefe 
particles were not only all of the fame fize, 
but were likewife regularly placed as in an ovi- 
duct, my curiofity led me to examine them 
with a microfcope, by which I at length con- 
-vinced myfelf that this prodigious number of 
particles was no other than fo many roundifh, 
ot oblong eggs, in which alfo there was a very 
difcernible motion. This induced me to open 
fome of them. But how great was my fur- 
prife on finding, that every egg contained a 
minute but perfect Worm lying folded up in 
it, like a young ferpent in its egg! Even thefe 
little Worms, when extracted from their eggs, 
moved themfelves exactly in the fame manner 
with the parent-infecét. This was an undeni- 
able proof, that this Worm was both ovipa- 
rous and viviparous; thus propagating its {pe- 
cies in the moft furprifing manner. But I re- 
turnto my proper tafk ; for this little animal, 
tho’ no longer than a young Frog ten days old, 
contained too many miracles to be publifhed in 
a few pages. 
To return therefore to the Frog itfelf, what 
Ihave faid fufficiently thews, how the eggs 
are difperfed, when they break’the ovary, and 
from thence roll into the cavity of the abdo- 
men. But I would fain know, by what art, 
regular motion, or contrivance an egg lying 
. Of DT NOSUERSC Sys. 
109g 
thus loofely in the body, can be conveyed into 
a narrow tube, whofe opening is placed very 
high up near the heart ? Certainly, the beft 
thing we can do on this occafion, is to own 
fuch a conveyance utterly inconceivable by hu- 
man underftanding, and humbly to acknow- 
ledge the narrow limits of our faculties. It can- 
not be denied, that at this time, the ovary is 
diftended very much towards the upper parts 
of the belly, by the great fize and number of 
the eggs itcontains; neverthelefs, the egos which 
poffefs the lower part of the ovary, never lie 
nearer than within two fingers breadth from the 
opening of the tube; and in the largeft Frogs, 
they are at a greater diftance. Let us fuppofe. 
them ever fo nearthetube, who will tell us bow 
they can get into the opening of it, which fome 
of the beft anatomifts could not difcover. The 
eggs have no motion of their own; nor are 
there any mufcles in the way to move them. I 
therefore conclude, that this motion of the eges 
of Frogs lies hid ina mytterious darknefs, too 
thick for human underftanding to penetrate. 
But however incomprehenfible this motion 
may be, we may derive from it great light into 
the motion of the eges in Women, in whom 
this tube is moveable ; fo that it can apply its 
mouth to the ovary, in order to receive the eps 
falling from this laft part, a thing which 
that induftrious anatomift Bidloo faw, and 
procured a drawing of. I have myfelf ob- 
ferved more than fifty times in F rogs, that the 
eggs which had broken loofe from the lobules 
of the ovary, had infinuated themfelves into 
the tube, and thro’ the tube into the uterus ; 
nor do I fee any manner of difficulty in con- 
ceiving how in any animals the egg once got 
into the tube, fhould from thence pafs to the 
uterus, the difficulty entirely lies in the paf- 
fage of the egg from the ovary to the tube. 
In the Frog there is all the reafon in the world 
to call this motion a miracle ; indeed, there is 
nothing to hinder us from giving it the fame 
appellation in all other animals. The caufes 
ot wonder are the fame in all; and in general, 
the motions of eggs ferve moft manifeftly to 
prove, that the human underftanding is con- 
fined within very narrow bounds. 
I have fometimes counted upwards of ele- 
ven hundred eggs in one Frog, all which are 
to pafs thro’ the narrow, immoveable mouths 
of thefe two tubes; nor can fuch paflage be 
looked upon as an eafy matter, as thefe tubes 
fcarce deferve to be confidered as fimple chan- 
nels, but rather as the horns of the uterus, 
which other animals exhibit. The white of 
the egg is formed in them, to furround the 
_Frog’s egg, or fcetus, and afford the young ani- 
mal nourifhment for fome days in the fame 
manner as the colliquamentum, or white, does 
the Chicken. On this account alfo, it is im- 
poffible to diftend thefe tubes with air at this 
time ; it is even a difficult matter to alter, even 
by fqueezing with the fingers, the fituation of 
the eggs at that time faftened within the tubes, 
the matter fupplied by them, ‘for the nourith- 
ment of the Frog’s feetus, which it moft regu. 
Ee larly 
