ing to the shape of their shells: (1) Flat-shaped coils (type
_Planorbis corneus_); (2) Oblong-shaped, somewhat like a trumpet (type
_Limnaea stagnalis_); and (3) Ear-shaped (type _Limnaea auricularia_).
_Limnaea auricularia_ is particularly suitable for deep waters, and _L.
pereger_, whose shell is of type 2, is a most valuable addition to the
food supply in any fish pond. It is one of the commonest of our
fresh-water snails.

Mussels (_Conchifera_) are another valuable article of food. There are a
great many different kinds, and the larger ones should, as a rule, be
avoided. _Sphaeriidae_ and _Pisidia_ are probably the best.

In many cases it is advisable to attempt the introduction of some flies
which are not present. There are several cases in which the May-fly has
been successfully introduced, and also the Grannom. Small _Ephemeridae_
seem to me preferable to any other flies.

With regard to suitable plants for comparatively deep water in ponds or
lakes, lakewort and stonewort grow on the bottom, and do not, as a rule,
attain any considerable height. White and yellow water-lilies also grow
in fairly deep water; the water-lobelia is also an excellent plant for
ponds.

In streams some of the best plants are water-crowfoot, water-starwort,
and the great water moss. Anacharis should not be introduced into any
water, either pond or stream, unless it can be kept down easily. It will
otherwise become an unmitigated nuisance.

Marginal plants are a very important consideration, and plenty of them
should be grown. Water-celery and water-cress are perhaps the best
food-producing marginal plants that can be grown. Bullrushes and
brooklime are also good, but the bullrushes must be planted
judiciously.

CHAPTER III

SUITABLE FISH AND SUITABLE WATERS

Having stocked his water with suitable vegetation and food, the next
matter which should engage the attention of the amateur, is what fish he
had better introduce. He should, where there is a fair chance of
success, introduce a trout of some sort, as they give better sport than
coarse fish.

The introduction of salmon into a river is not likely to be attempted by
the amateur, but the head of salmon frequenting a river is undoubtedly
affected in the most marvellous manner by artificial means. In Canada
and the United States this is particularly remarkable, but the
operations are conducted on a gigantic scale.

In the case of a stream or river where brown trout a