[ 8 72 ] 
weeks, they - are fit for the operation; for, like hens,' 
they have fmall eggs in their ovaries as foon as they 
have laid their former clutch of eggs. 
When a fifh is intended to be caftrated, it muft; 
be held in a wet cloth, with its belly upwards ; then 
with a fharp pen-knife, with its point bent back- 
wards, or other well-adapted inftrument, the opera* 
tor cuts through the integuments of the rim of the 
belly, and in doing this he carefully avoids wounds 
ing any of the inteftines. As foon as a fmall aper* 
ture is made, he carefully inferts a hooked pen-knife, 
and with this he dilates this aperture from between 
the two fore-fins, almoft to the anus. From the 
back of this inftrument, being blunt, the danger of 
wounding the inteftines is avoided. He then, with 
two fmall blunt filver hooks, of five or fix inches 
long, and of the * form hereunder described, by 
the help of an afiiftant, holds open the belly of 
the fifh ; and, with a fpoon or fpatula, removes 
carefully the inteftines from one fide. When 
thefe are removed, you fee the ureter, a fmall 
vefiel, nearly in the direction of the fpine ; and. at 
the lame time the ovary, a larger vefiel, lying before 
it, that is, nearer the integuments of the belly. 
This laft vefiel you take up with a hook of the fame 
kind with thofe before-mentioned, and detaching it 
from the fide far enough for the putpofe, divide -f it 
tranlverfely with a pair of fharp fcifiars ; remem- 
f Mr. Tull has frequently, to prevent the re-union of the divided 
ovaries, by which the effedt of the operation might be defeated, 
taken out part of them, and neverthelefs the fifh have furvived. - ' 
berin g 
