IMPREGNATION OF EGGS IN TROUT BREEDING. 601 
than two feet deep; the depth depending upon the size of 
the rollers, which in a short race may be quite small and the 
box not more than eighteen inches deep. The box is set 
directly in the raceway, and intended to fill it completely. 
The water enters in the direction of the arrows, and may 
either enter with a fall over the top of the box, as seen in fig. 
124, or the top of the box may be cut down until the water 
will enter on the level at - Fig. 125. 
which it is intended to stand 
over the screens. E 
F (fig. 124) is a screen 
intended to prevent the fish 
from running beyond the 
race, or getting into the 
lower part of the box. It 
may extend to the bottom, 
or be arranged as seen in the 
engraving. D is a screen at 
the front of the box, also 
intended to prevent the fish C&S St 
from getting below. When Peet of opui POr 
the eggs are to be taken this screen is raised on hinges to an 
upright position, and confined by a spring catch or latch as 
seen at E (fig. 125). This confines the fish which may happen 
to be in the race and none of them can get below. The pan 
is then lowered to its position, the roller turned and the 
eggs taken. When the operation is finished the screen D 
is again lowered, the button turned and the work is done. 
If the box is wide, say four feet, it is more convenient to 
have the pan made in two or three sections, inserted in a 
light frame, as. the eggs can be more easily carried in and 
poured out of a shorter pan. It is better perhaps to make 
the screen D to open in the middle, having hinges at both 
sides. Then one half will keep the fish in the pond, and the 
other half the fish in the race, from running into the well. 
The box can be made of any length from four feet to forty 
