Flow to obtain it. 89 
will grow to a considerable extent in water, such as white clover, 
buttercup, etc. I found this out, as many other things have been 
found out, quite by accident some years ago. The grass border 
to a pond containing some trout fry had not been cut so carefully 
as usual, and IJ noticed that where plants growing on the margin of 
the water had put out their runners and were endeavouring to 
grow in that element, there the little fish congregated and pro- 
duced very much better specimens than were to be found in the 
body of the pond. I have since several times cultivated these 
land plants as marginal semi-aquatics, and with favourable results. 
On another occasion, some trout fry which had accidentally 
escaped from a rearing box were afterwards found in a water plant 
bed, and in a month they had quite doubled the size of their 
fellows, who were being reared by artificial means. The water- 
cress was one of the plants which grew in this particular place, 
and under the shelter of which the little fish had taken refuge- 
Watercress requires to be planted where there is a comparatively 
warm spring, in order to have a good crop early in the year, but 
in many sheltered situations it will make good headway in April 
by the heat of the sun alone. It can also be forced very rapidly 
under glass, and it is worth while doing this about fry ponds and 
their raceways. 
Another excellent marginal plant is the marsh marigold 
(Caltha palustris). Vike the watercress, it may be planted at the 
head of a pond, along the sides of the stream, and also all round 
the sides of the pond itself, at any convenient places. It is a 
useful plant for fry ponds, or any rearing ponds, and I have grown 
it about my own for many years with advantage. Rabbits do not. 
eat it, which cannot be said of the watercress, for I have found 
the latter quite exterminated by these rodents where the marsh 
marigolds were left untouched. They are very easily cultivated, 
and should be planted in spring, and they never become a pest, 
which is very much in their favour. I have succeeded in getting 
a variety that produces fine double flowers, and either these or the 
single ones are exceedingly effective when cultivated in clumps. 
They have the advantage of being very hardy, and once 
established are easily propagated, either by means of seeds or 
offshoots. I have seen trout fry harbouring under the shelter of 
