398 Wisconsin state agricultural soceity. 
the impregnated eggs of the same age have turned into fish. 
Now the test of the value of any hatching arrangement is the 
length of time in which unimpregnated eggs will remain of a nat¬ 
ural color. If they will remain apparently good until after the 
impregnated eggs with them of the same age are hatched out, 
then the arrangement is about as near perfect as it can be. It 
has been insisted that the earliest hatched eggs were best, and also 
that eggs hatched in a temperature of 40° to 45° made the hardiest 
fish. Our experiments thus far seem to indicate that there is no 
difference, fish from eggs spawned in March doing as weli as those 
from eggs spawned in October, and eggs hatched in 50° doing as 
well as those hatched in 35°. 
Growing young trout. — This has always been the rock upon 
which new beginners have been shipwrecked. Yery few persons 
have found any special difficulty in hatching out the eggs, or in 
keeping the young fish until the sac was entirely absorbed. But 
a very general want of success has been felt in rearing the brook 
trout from the age of forty-five days to the age of three or four 
months. There must be some reason for this; let us see if we 
cannot find it. The failure must lie in one or more of four cir¬ 
cumstances. Either the eggs are not good in the first place, that 
is, imperfectly developed, or for some reason producing weakly 
fish, or the water in which the experiment is tried is not adapted 
to the young fish, or the food which is commonly used is not the 
proper food, or the fault lies in the person feeding them. Now, 
does the fault lie in the eggs? We have no doubt that fish some¬ 
times, from a lack of vitality, etc., produce imperfect eggs, and we 
have just as little doubt that the greater part of such eggs die be¬ 
fore they are many weeks old. A few may survive the hatching 
process and absorption of the sac, but their number is exceeding¬ 
ly small. Our reasons for this belief are as follows: First, we 
have often taken the eggs from fish evidently diseased, and kept 
them in a place separate from others. In nine cases out of ten it 
was impossible to impregnate these eggs at all, and of those which 
were impregnated not one-tenth would live until the fish became 
plainly visible to the naked eye, and a still less proportion would 
survive until the sac was absorbed. Then, again, if the failure to 
raise the young fish lies in the imperfection of the egg, we should 
