112 The BOOK of NWA PUR Et on, 
On opening afterwards fome of the lobes, 
all the foregoing particulars appeared {till more 
diftincily; the caufe of the blood-veffels a- 
mongit the eggs being very difcernible, e, as 
likewife the manner in which the eggs were 
placed upon the fmaller ramifications of thefe 
veflels. When I had attentively furveyed and 
confidered all thefe things, I judged them to be 
the rudiments of the eggs, that were to be fhed 
the enfuing féafon; tho’ afterwards the irre- 
gularity of their figure, and their difference in 
fize, made me alter my opinion. 
Finally, I found at the bottom of the mem- 
branes, which conftituted the globules, and 
amoneft the eggs I have juft now mentioned, 
fome empty and very delicate membranes, Fig. 
1v. aaa, which had ferved to inveft the eggs that 
had been already difcharged from the ovary; in 
the fame manner as it appears in the clufter of 
eggs in Hens, which {till retain, after the yolks 
have left them, the little membranes and cells 
which furrounded thofe yolks; though, in 
courfe of time, thefe traces. contract them- 
felves by degrees, and entirely difappear. | 
Thefe particles were moft beautifully inter. 
woven with blood-veffels, to which they were 
fixed as to fo many ftalks, 54; as I have en- 
deavoured to {hew both one and the other, and 
at the fame time one of the largeft blood. 
veffels, cc; but all of them confiderably mag- 
nified. | 
This obfervation gave me reafon to think, 
that the eggs I have been laft {peaking of; 
might be, as it were, like fruits, which had 
not as yet attained their due point of perfection, 
and might wither and drop off, before they 
did fo; and I found this to be the cafe, even 
with perfect eggs, that had remained in the 
ovary and abdomen, as I have in part repre- 
fented under the letter} of the third figure. 
Thefe little membranes, which I have been 
defcribing, were torn, as it -were, and {0 col- 
lapfed as to form a fmooth plain furface; for 
which reafon I exhibit only a few of them. 
But it is time to fee now what becomes of the 
eggs, when they are difcharged by the crea- 
tures now under confideration. 
Of the manner in which the young Frogs or Tadpoles grow in their parent's eggs, 
and are in due time hatched or delivered from thew. 
ott very next day after the eggs had been 
difcharged, being the 18th of April, 
they were of the bignefs reprefented at (1) ; 
and the albumen, or white, which furrounded 
them, was very inconfiderable: but I could 
fee they grew from one minute to another, fo 
that the day next following they were of the 
fize at figure (2). The white, in proportion 
as the water gradually penetrated it, grew on 
every fide more and more clear and tran{pa- 
rent; but the infide, which immediately con- 
tained the embryo Frog, rather looked like an 
agate. As to the fcetus itfelf, I could difcern 
no alteration in it. But not content with ex- 
ternal appearances, I refolved to examine tho- 
roughly thefe eggs; but the furprifing tough- 
nefs of the white threw fuch obftacles in my 
way, that all my endeavours ended in nothing: 
and though I, at laft, ftripped the embryo of 
the coats and other fubftances in which it was 
wrapped up, it was fo crufhed, and otherwife 
difturbed by my handling it in the operation, 
that I could not by any means fatisfy my cu- 
riofity. 
This difappointment obliged me to take 
another method. ‘I put a large number of 
thefe eggs into different liquors, in hopes fome 
of thefe fluids might prove a fufficient men- 
ftruum to diffolve the white. At the fame 
time I boiled, with the fame view, fome of 
thefe.eges in water; by which means I indeed 
fucceeded, but not as perfectly as I defired. 
However, I could fee that the fkin of the en- 
clofed Frog was regularly wrinkled, as in boil- 
ing it had loft by evaporation fome of its hu- 
mours. 
On furveying the next day the eggs I had 
put into the other liquids, I found that the 
whites had been coagulated by the liquor, 
whofe effects I firft attended to, fo as to appear 
of a beautiful roundnefs, like bunches of grapes. 
In colour they ina manner refembled an agate, 
or the boiled egg of a Lapwing. The little 
enclofed animal was alfo coagulated, fo as not 
to fall afunder on diffection, though I could 
then more eafily diveft it of the yolk. 
In another liquor the eggs had acquired a 
purple colour; but very little of the white was 
diffolved. I therefore paffed to a third liquor, 
in which I found the white of the eggs was 
become more milky, and was a little diffolved; 
and it had befides loft a great deal of its clam- 
minefs and tenacity. The little Frog itfelf was 
increafed to twice its fize, and all its contents 
had in fome meafure contracted acolour: both 
which circumftances afforded me a very con- 
venient opportunity of examining thoroughly, 
and with great care, the firft rudiments of this 
little animal. “Bie 
The whites of the eggs in the fourth liquor 
had affumed a greenifh hue, and wanted little 
_of being entirely diffolved; fo that here alfol 
could very conveniently furvey every part of 
the young Frog, efpecially as this was alfo en- 
tirely coagulated in the fame manner with the 
yolk of a boiled egg. ‘Thefe were the different 
effects, on various parts, performed by one and 
the fame liquor. On examining, therefore, 
with a microfcope, the enclofed young crea~ 
ture, I found it to confift entirely of minute 
grains, which were in a manner uniformly 
divided, and were yellow and. tranfparent, 
aig without 
