PROPAGATION OF FISH. 247 
up for the quantity that must inevitably be washed away 
by the water, without coming in contact with the latter 
in the natural process. 
The impregnation of the eggs may be ascertained by 
their alteration in color, exchanging the orange for a 
yellow tinge, and by the presence of the black spots, as 
in the natural process ; when it is thoroughly effected, the 
w^ater is poured off and fresh supplied. Care should be 
taken to preserve the most perfect cleanliness ; sediment 
is very destructive to tlie vitality of the embryos. 
There are several modes of disposing the spawn, 
either in boxes, half full of white pebbles, with sides 
perforated with holes, or in wicker baskets, either with 
or witliout pebbles. It is nowhere recommended to 
cover the eggs with sand ; but as the fish naturally pur- 
sues this course, and as great injury is produced by sedi- 
ment and delicate aquatic plants, and as disease is com- 
municated from one to another, I would decidedly advise 
that it should be given a trial, and the comparative 
results observed. It would certainly preserve the eggs 
from many of their principal dangers from water-bugs 
and insects, from dirt and infection, and can do no injury 
to the young fry, which, when hatched, readily make 
their way through it to the pure water. 
These baskets or boxes are arranged in various ways, 
according to convenience, and will do w^ell so long as a 
pure stream of spring water, about 32 to 35 degrees of 
temperature, flows through them, wdiether directly from 
the spring or intermediately through one another. By 
allowing a few inches' fall from one to another, the water 
is aerated and its vivifying powers increased. Care must 
