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ingenious Raefel, the large Water-Frogs have 
voices as loud as the bellowing of bulls; to efleft 
which, they pufF up their cheeks to a furprizing 
magnitude. However, the males only croak, 
the females remaining filent; and the voice of the 
former feems only the call of courtfhip. It is 
certain that, during the feafon of copulation, the 
ioudnefs of their croaking is in fome places very 
troublefome ; for then whole lakes feem to be vo- 
cal, and their various diflbnant notes almoft ftun 
the neighbourhood. Before rainy weather, they 
alfo exert their voices to the utmoft ; they are then 
heard to pour forth their tones with unceafing af- 
fiduity, and to welcome the approach of their fa- 
vourite moiflure. No barometer more certainly 
prognofticates an approaching change of weather; 
and this may probably ferve to explain an opinion 
which fome people entertain, that there is a cer- 
tain month in the year, called paddock-month, in 
which Frogs never croak: while tlie fail is, that, 
in the hot feafon, when the moifrure is dried up, 
they neither enjoy health nor food in the fime pro- 
portion as during rain; and this renders them 
mute and inaftive. 
As Frogs clofely adhere to the backs of their 
own fpecies, fo it has been proved, by repeated 
experiments, that they alfo adhere to thofe of 
filhes. They will at times ftick to the backs of 
carp in ponds; and, fixing their fingers in the cor- 
ner of each eye, in this manner they are often 
caught together, the carp being blinded, and very 
much emaciated. Whether this aft proceeds 
from the defires of the Frog when difappointed of 
it's proper mate, or whether it be the efie6l of 
a natural enmity fubfifting between Frogs and 
filhes, is not eafily determined. However, the 
following ftory, as related by Walton, might in- 
cline us to adopt the latter opinion. ' As Du- 
bravius, a bifliop of Bohemia, was walking with 
a friend, by a large pond in that country, they 
faw a Frog leap on the head of a pike, which lay 
very quietly by the fliore-fide; when the Frog 
having exprcfled malice or anger by his fwollen 
cheeks and flaring eyes, did ftretch out his legs, 
and embrace the pike's head, and prefently reached 
them to his eyes, tearing with them and his teeth 
thofe tender parts : the pike, irritated with anguifh, 
moved up and down the water, rubbing himfelf 
againft weeds, and whatever he thought might rid 
him of his enemy; but all in vain, for the Frog did 
continue to ride triumphantly, and to bite and 
torment the pike till his ftrength failed; and then 
the Frog funk with him to the bottom of the wa- 
ter. Prefently the Frog appeared again at the 
top, and croaking, feemed to rejoice like a con- 
queror; after which, he immediately retired to his 
fecret hole. The bifhop, who had beheld the bat- 
tle, called his fiflierman to fetch his nets; and by 
all means to get the pike, that they might declare 
what had happened. The pike was drawn forth, 
having both his eyes eaten out; at which, when 
they began to wonder, the fifherman afiured them 
he was certain that pikes were often fo ferved.' 
The Frog affords the curious in microfcopical 
obfervations a very beautiful view of the circula- 
tion of the blood ; but the method of examining it 
to advantage was firfl difcovered by the ingenious 
Dr. Stuart. This gentleman made ufe of the fo- 
lar micro fcope in a particular manner adapted to 
that purpofe. He opened the fkin of the belly 
from near the anus to the throat ; and then giving 
it a little fnip fide-ways, both at top and bottom. 
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and flicking a fifli-hook into each corner of the 
fl<;in, it was eafily extended before the microfcope; 
and exhibited on the fcreen the mofl beautiful 
view imaginable of the veins and arteries of the 
flcin, with the blood circulating through them. 
In the arteries, thus viewed, the blood is feen to 
flop, and recede a litde at every pulfation by the 
dilatation, and rufh forcibly on again by the con- 
traftion of the heart; while in the veins it ever 
keeps the fame equable and uniform current, with 
a furprizing rapidity; and, when the fcreen is re- 
moved farther back, and the obje£l by that means 
more enlarged, the alternate expanfion and con- 
traftlon of the fides of the arteries are very vifi- 
ble. After this, the abdomen of the Frog' being 
opened, and it's mufcles extended before the mi- 
crofcope in the fame manner v;ith the fkin, their 
ilrufture is beautifully difpkved, being all com- 
pofeu of bundles of tranfparent firings of fibres, 
lying parallel to each other, and joined by a com- 
mon membrane. When this has been fufficiently 
examined, a part of the entrails being pulled out 
and extended with the mefentery, one of the fineft 
viev/s of the circulation of the blood is exhibited: 
that fluid is feen pafllng through numberiefs vef- 
fels at one and the fame inflant, in fome one way, 
and in others direilly contrary. Several of the 
vefTels are thus magnified to more than an inch 
in diamiCter, and the globules of blood running 
through them appear nearly as large as pepper- 
corns; while, in many of the minuteft vefTels, only 
fingle globules are able to find a pafTage, and that 
too by changing their fnape into an oblong fphe- 
roid. The pulfation and acceleration of the blood 
in the arteries are alfo very agreeably fliewn by 
this means. As the animal, under examination, 
becomes languid and near expiring, the blood in 
the arteries will often flop on a fudden, and feem 
as if it were coagulating, and then run back for 
fom.e time ; after which it will again recover it's 
natural courfe with a great deal of rapidity. A 
due confideration of the foregoing particulars may 
pofTibly account for the intermifTions, flarts, and 
irregularities, perceived in the pulfes of perfons at 
the point of death. 
Frog, Edible. This animal differs from the 
common Frog in having a high protuberance on 
the middle of the back, which forms a very fliarp 
angle. It's colours alfo are more vivid, and it's 
marks more diflin£l, being a pale or yellowifh 
green, imprefTed with rows of black fpots from the 
head to the rump. Both this and the common 
Frog are eaten in fome countries. ' In the mar- 
kets at Paris,' fays Pennant, ' v/e have feen vvholc 
hampers full, which the venders were preparing 
for the table, by fkinning and cutting off" the fore- 
parts, the loins and legs only being kept.' 
Frog, Green, or Small Trbe-Frog. This 
fpecies is diflinguifhed from the other kinds by 
their colour, the minutenefs of their fize, and by 
their fitting on the leaves of trees. In Germany 
and Switzerland they are frequently feen on trees 
and fl:irubs in the evening; and, from their note, 
they miight be miflaken for birds rather than: 
Frogs. They feem to be the cicada of Virgil. 
Frog of Martinico. This animal, which is 
the mofl beautiful of the genus, is of a grey co- 
lour with yellow and black fpots or flripes ; and 
lives folely in the woods, where it makes a noife in 
the ni2;ht-time fomewhat fimilarto the barking of 
a dog. 
Thefe Frogs are above a foot in length, with- 
out 
