240 Flow to obtain it. 
in nursery ponds this is not so, therefore the want must be 
supplied artificially. Every one who knows anything about trout 
knows how they delight in a rise of the water, and how much 
more easily they are caught at such atime. An examination of 
the contents of a few of their stomachs will show, in addition to 
the ordinary food, consisting of worms, flies, etc., a proportion of 
gravel and earthy matter. It is sometimes very desirable to make 
artificial spates in fish ponds, which is easily done by damming 
back the water and letting it off through the ponds. Care 
should be taken that the flow through the ponds is not materially 
lessened in performing this operation. 
Earth has a beneficial effect in many ways, and in some cases 
has been found to be a cure for fungus. Fry are very liable to be 
attacked by fungus, and too much care cannot be exercised in 
endeavouring to keep clear of it. Avoid any uncharred wood- 
work about the ponds. Be careful that no roots of trees that 
may have found their way into the raceway are cut in the spring. 
I once saw a raceway that had been cleaned and had its sides 
trimmed in early spring, and in doing this the roots of several 
trees had been cut away. Ina short time the end of every stump 
was covered with fungus. It is also largely produced on the 
pond bottoms when they become foul. Therefore, keep them 
clean, for if they be allowed to remain dirty mischief is sure to 
accrue to the fish. One of the most fertile sources of danger is to 
be found in the accumulation of greasy or fatty matter on the 
surface of the water, the result of artificial feeding. It should be 
got away as often as it accumulates. Every time the fish are 
artificially fed, more or less of this grease must be set free, and, 
if not attended to, it will float on the surface of the water. The 
little fish, when swimming near the surface, will come in contact 
with it, and it will adhere to their fins and bodies, and will 
become a suitable zzdus for the germs of the fungus. It can 
easily be kept from accumulating by breaking up the scum which 
it forms, and floating it on to the outlet screen, or by skimming it 
off the surface of the water. 
Should fungus from any cause attack the fish salt is a remedy, 
and it may be applied either by putting it through the ponds, or 
by netting out the affected fish and giving them a salt bath. In 
