The BuQ2O.K. of 
means the tube. Befides, the ovary of Frogsis 
never found to have naturally that figure, which 
Jacobeus very raflly gives it, thought is to be 
obferved, that the uterus, when loaded with 
eggs, is found on diffection to have, in fome de- 
eree, {ach an appearance. ‘Therefore, the oval 
eftium, or mouth, which this author mentions, 
is, in my account, really the opening of the tube 
into the uterus, which, properly {peaking, fhews 
itfelf where the tube ends, and the uterus com- 
mences. See Tab. XLVII. Fig. rv. letters f/, 
where | have at large defcribed all thefe parts. 
Such being exactly the cafe, and it being at the 
fame time certain, that the inferior extremity of 
the tube has no communication with the ovary ; 
and that no eggs can enter there from the lobules 
of the ovary, which are perfectly clofed; and 
as likewife M. Jacobeeus could not difcover the 
upper orifices of the tubes, I would be glad to 
know in what manner this author can explain the 
paflage of the eggs from the ovary, into and 
through the tube. I really cannot conceive. how 
be can acquit himfelf of this talk; fo that he has 
in good earneft made the motion of the egg, from 
‘the ovary more obfcure, than he is pleafed to 
fancy I had done. But I, by no means intend 
-to enter the lifts with this gentleman, or impra- 
-dently treat him with rough language; for it is 
‘not in fearch of glory to ourfelves, but the great 
Creator, that we ought to furvey and examine 
his works. For this reafon, I rather look upon 
myfelf as under an obligation to this iluftrious 
naturalift, for having condefcended to criticife, 
and bring to the teft my experiments concerning 
Frogs; and, in the fame fpivit, I muft tell him, 
that he can never mifs finding the opening of the 
tubes near the heart, provided he looks for it a 
‘little after the Frogs have depofited their eggs. 
At this time, even the whole uterus may be dif- 
tended with air through the tube; and, on the 
other hand, from below, upwards, the tube thro’ 
the uterus. What is ftill more, thefe openings 
of the tubes may be then difcovered without any 
diflections, by only blowing flightly through a 
pipe in the adjoining part of the heart. But 
none of thefe experiments will fucceed, whilft 
the eggs are only in their paflage through the 
tube, at which time, perhaps Jacobeus furveyed 
thefe parts. ‘hus the natural opening of the 
tube becomes very difcernible to thofe who take 
aright method to difcover it. But is it not fur- 
prifing, that the defcription. given by me, and 
which Jacobeus muft have feen, as he quotes it, 
did not open his eyes; for, though fhort, it is 
very plain and intelligible. Mankind is liable to 
error; but, to perfiltin it, after friendly admo- 
nition, fhews a perverfe arrogance, that will not 
fabmit to acknowledge its miftakes. 
It is now time to fpeak of the egg’s paflage 
through the tube, from the ovary into the ute- 
ras, which is indeed not on'y difficult to exprefs 
in words, but even to conceive, fo that in the 
whole {cience of anatomy, equally abftrufe and 
myfterious, I muft own, that this is very ob- 
108 
* Natusalits have been perplexed extremely to account for the V 
nave been fwallowed in food by the Frog, for this would not be their place. 
were created with the human frame; 
ficaated. ‘They cannot | 
that the Worms found in our inteftines, 
of livjng : it is much more firongly probable here. 
NATURE; of, 
{cure in many other animals, but in Frogs, it is 
altogether incomprehenfible; for the ovary, as 
Iremarked above, and am ready to demon({trate 
in the Frog itfelf, does not in any way commu- 
nicate either with" the tube or with the uterus. 
The opening of the tube cannot by any means 
move. itfelf towards the ovary. ' Befides, there 
are no other mouths at which the eggs can be 
received, than the narrow membranaceous ori- 
fices of the tubes, which above grow to the 
membranes of the heart; fo that there does 
not appear in this place the leaft trace of any 
eval mouth, by which it is faid, that the tube 
opens itfelf about the inferior region of the 
ovary ; for it is very eafy to feparate the tube 
and ovary from one another: and the ovary 
afterwards extracted from the body, may by 
itfelf be diftended with air, and dried, not 
having the leaft aperture to let the air efcape, 
or the leaft mark of ever having had one. . 
Ihave fometimes diftinctly obferved in breed~ 
ing Frogs, that whereas the ovary of one that I 
diffected, about the beginning of April, ftilk 
contained all its eggs; that of another, open- 
ed a few. days afterwards, had loft the greateft 
part of them, Tab. XLVII. Fig. v.a. I could 
likewife, at the fame time, eafily difcover a 
great many of the eggs that had efcaped out 
of the uterus, and were broken, lying here 
and there in the abdomen 444, between the 
lungs, and under the finufes of the ftomach 
and inteftines, among the membranaceous parts 
of the vifcera, and elfewhere. Some alfo ap- 
peared near the opening of the tubes ¢. Others 
were {till adhering to its infide ddd, part in its 
higher, and part in its lower region. I even 
difcovered an egg lying at the very mouth of 
the tube ¢, and in what manner the eggs were 
leifurely forced thro’ the extremity of the tube 
into the uterus ff. I obferved alfo, that the 
greateft part of the eggs ftill adhered to the 
uterus ; which I here reprefent two ways. 
Firft, I exhibit the uterus as it naturally ap- 
pears g, with the contained eggs vifible thro’ it, 
but very faintly ; and on the other fide I re- 
prefent it as it looks, after having been mace- 
rated in water, or on its beginning to dry, after 
being expofed to the open air for fome time; 
in both which cafes it very diftin@ly fhews the 
egos {hut up in its cavity 4. I reprefent befides, 
lower down, the extremity of the double ute- 
rus z,which is inferted into the ftraight gut, about 
half an inch from the opening of the tubes into 
the uterus. Near the heart appears the begin- 
ning of the great artery, with two {maller arte- 
ries {pringing from it & On each fide, near 
the heart, are openings of the tubes//; and I 
have reprefented the lungs as bearing upon 
thefe openings mm, in order to render their 
fituation next above the lungs more diftinél 
perceivable. It is very remarkable, that living 
Worms are almoft always found in the lungs 
of Frogs; Ihave often met with fix in one 
Frog.* 
VYorms found in the inteftines ; but thefe are much more ftrangely 
The opinion of Vallifnieri is, 
and that the bowels are their natural aad proper place 
The 
