ICHTHYOLOGY. 751 
tHe bream, and the Carp, require not much care, of courfe, 
nor fo mail}' precautions, as others that will die foon after 
being taken out of the water, e. g. the perch, the fmelt, 
and the bleak ; foine, as the trout and loche, have fo lit¬ 
tle life, that they die if put into ftill water; therefore the* 
veflels in which thefe latter are tranfported muft be kept 
always in motion, even when the carriage ftops; it is belt 
alfo, when the weather is very warm, to travel only at 
night. Another precaution very necefiary to be obferved 
is, not to fill the calks in which they are carried, left 
they ftrike their heads in darting to the top of the water. 
In long journeys, the water muft be changed from time 
to time, efpecially for trout and tench. In fummer the 
calks fhoulti not contain above half the quantity of fifh 
that might be put into them in winter, as in hot weather 
they greatly delight in frefli cool air; and indeed in all 
fealons there fhould be a free current of air let into the 
calks. Yet, in leaving the bung-hole open, care fhould 
be taken that the motion of the vehicle does not make 
the water fplafli out too violently, norcaule too much agi¬ 
tation within, as thereby the fifh, driven one againft .the 
other, may be wounded or killed ; a wifp of ftraw or fbme 
bits of thin board infide the calk* will in fome meafure 
prevent this. 
It is hardly neceffary to fay, that, in catching fifh for 
thefe purpofes, great care fhould be taken not to hurt or 
bruife them. Fifh of a full fize fhould alfo be chofen, of 
three or four years old; fifh of a year old are too young. 
When you want to breed the voracious fifh, you fhould 
put in with them fuch as ufually ferve them for food; and 
of thefe, for economy-fake, we would facrifice fuch as are 
of lealt value for the table. 
It is remarkable that fo few fpecies of this clafs of the 
animal kingdom have been tranllated from their primitive 
haunts, and made fubfervient to man by domeftication. 
Only three kinds have been tranfported from foreign 
parts .into Britain ; the carp, the tench, and the gold-fifh. 
Double that number are domelticated with fuccefs upon 
the continent; but even this, in all probability, is but few 
to what might be rendered fubfervient to the fame pur- 
pofe, by the induftry of man. There can at leaft be en¬ 
tertained no doubt that thofe domefticated upon the con¬ 
tinent would thrive equally in Britain. The Cyprinus 
caraflius is found indigenous in many of the rivers in 
England, where it is called the rudd. It is reckoned a 
fuperior fifh to the carp in many refpefts, yet it has never 
been domefticated in its native country, though reared 
with great advantage in the fifh-ponds of Sweden. The 
Cobitis foflilis is a fifh unknown in this country; but is 
domefticated, with profit, in the ponds at Stockholm, and 
might, with equal propriety, be tranflated into thofe of 
Scotland. In the fame manner the Cobitis barbatula, 
which was introduced into Sweden by Frederic I. might be 
made an inhabitant of our artificial ponds. The Salmo 
thymallis of Linnaeus, known in England by the name of 
grayling, is one of the beft fifties both for fport and the 
table, and might eafily be tranfported here from the ftreams 
of Derbyfhire, its native refidence. Both eels and charr 
might be rendered ufeful pond-fifh ; as neither are too 
delicate for tranfportation ; and, from experiments al¬ 
ready made, the certainty of their thriving is fully elta- 
bliftied. * 
Sea-fifh may be brought to live and breed in rivers; for 
it is to be obferved, that the oxygen and hydrogen drawn 
by the new chemiftry from fait water have exaftlv the 
fame properties as when extradited from frefli; fo that, if 
by decompofition the oxygen of the water helps to preferve 
the circulation of the blood, or its hydrogen be taken for 
nourifhment into the inteftinal canal, the fuftentation the 
fifh receives is equal whether the water be frefli or fait. In 
proof of this, a vaft number of fifli fpend one half of the 
year in the feas, and the remainder in rivers and ftreams ; 
and thefe are found to have the fame conformation and 
organization as thofe which never quit their native place, 
whether fait water or frefli. 
As for temperature, deep waters are nearly alike in 
every country; but moft animals can endure an increafe of 
cold' rather than of heat; therefore bring fifties from the 
fouth into lakes and rivers of the north, rather than the 
contrary. And even fhould thefe northern waters be lia¬ 
ble to be frozen over, ftill .the tithes from the fouth will 
not be deftroyed. They will lie at the bottom during 
the winter; and, fhould fufficient air be prevented from 
reaching them, or fhould the cold feize them too fuddenly, 
will only be thrown into that torpor which preferves life 
by fufpending its chief fundftions, which the return of a 
more favourable feafon will not fail to reftore. 
Fifties that have been taken out of the fea, or from the 
mouths of rivers or brifk ftreams, muft not be put into 
fmall ponds or ftagnant waters, as that will affeift them 
much more than a change of climate; it muft be contrived 
to have a continued Itreanr of renewed water palling, 
through the place they are put in ; and large ftones may 
be fo placed as to increafe the roughnefs and agitation of 
the water, and at the fame time perhaps to fupply the 
place of the rocks and inequalities in their native ftreams, 
againft which they will rub themfelves and call their 
fpawn. The males are generally more numerous than the 
females ; in fome fpecies nearly double ; yet one male is 
fufficient to fecundate the fpawn of many females. There¬ 
fore, in order to preferve and increafe the breed, throw 
back the largeft and lieavieft females when caught, and 
keep the males for food; the females are generally biggeft, 
and may eafily be diftinguifhed by other marks, as colour. 
See. which we fhall more particularly point out in treat¬ 
ing of the different genera and fpecies under their proper 
heads. 
It is well known, that the fame fpecies of fifli are not 
equally good in all places. Even in the fame river, the 
fifh will be of a good flavour in that part which lies above 
a town, or any place where a dirty ftream runs into it; 
but below a populous town, where much naftinefs is 
thrown in, the fifh of the fame river will be very ftrong 
and ill-tafted. This has been remarked by many writers, 
particularly Rondeletius ; and fhould not be difregarded 
by thofe who would improve the breed of fifh. See far¬ 
ther under the word Fishpond, vol. vii. p. 430. 
There are various inodes, by no means expenfive, of 
fattening fifties in a fhort time, efpecially carp ; they foon 
increafe in fize if fed with a pafte or bread made of hemp- 
feed, or peafe and beans boiled, or by throwing dung 
into the ponds, particularly fheep’s dung. With fuch helps 
they grow much quicker, and are fooner in a ftate of 
fpawning, and the males are capable of fecundating a vaffc. 
number of eggs for a great many years. But, if repefe 
be added to nourifhing food, they may be fatted ftiil 
fooner for the table ; thus fome have contrived to pierce 
the air-bladder of fiflies, to abridge their aftivity, and keep 
them in a ftate of reft. Carps may be fufpended out of 
water, fo as to allow no motion whatever to their fins; 
then wrap them in a thick covering of weeds or grafs, 
which keep continually wetted, and they will foon grow 
fat and of a delicate flavour. Another mode is to deprive 
them of the means of procreating, like oxen, ftieep, &c. 
It is found, by experiment, that fifties, efpecially the pike, 
maybe cut open, and the ovary or milt-veffel taken out, with 
little prefent inconvenience; and that fuch fifties afterwards 
become very fat, as the nouriftiment which would go 
to the propagation of the fpecies now helps to increafe the 
fize and flavour of the mutilated animal. This was firft 
praflifed by Mr. Tull, in order to prevent the exceflive 
increafe of fifti in fome of his ponds, where the numbers 
did not permit any of them to grow to an advantageous 
fize. But he afterwards found, that the caftrated fifh grew 
much larger than their ufual fize, were more fat, and al¬ 
ways in feafon. This operation may be performed both 
on male and female fifh ; and the moft eligible time for it 
is when the ovaries of the female have their" ova in them, 
and when the veflels of the male analogous to thefe 
have their fieminal matter in them } becaufe at this time 
theft) 
