no Hoiv to obtain it. 



The sides of the raceways should be planted the whole 

 length with suitable vegetation. Watercress (Nasturtium 

 officinal*) is excellent for the purpose, and also the marsh 

 marigold ( Calf ha palustris). The pretty little golden saxifrage 

 ( Chrysosphnium oppositifolium ) may also be used with advantage, 

 and the brooklime ( Veronica beccabunga). There are many land 

 plants that do very well in water for a time, and I have found that 

 the decay of these plants is favourable to the growth of animal 

 life (see page 88). No floods or freshets should be allowed to 

 sweep through these nursery ponds. This can easily be guarded 

 against by a sluice, or what is more simple, allowing the water to 

 enter them through a four-inch pipe. 



They should be made as tempting for the little fish as 

 possible, by planting aquatic vegetation about them. It may 

 sometimes be desirable to place a screen across the end of the 

 lowest pond in the position of the dotted line at K, but should 

 the fish be found to collect above this screen they must be fed or 

 they will die, and in feeding them all pains should be taken to 

 coax them away from the screen and get them up to the head of 

 the pond. As soon as the bulk of the fish have settled in the 

 ponds, remove the screen and let them have full scope to go 

 where they like. These ponds may be made accessory to an 

 artificial ova bed or a spawning race, or they may be stocked with 

 fry that have been purchased or hatched elsewhere. 



The screen, if used, should be made loose, to slide in a 

 grooved frame, or it may be simply fixed by embedding the frame 

 in the sides and bottom of the pond. It will only be required for 

 a short time after the fry are introduced, and may then be taken 

 out and stowed away to use another season. It will be seen by 

 the diagram (Fig. 3) that the ponds and raceways are arranged in 

 the most compact form, instead of having them ranging over a 

 long expanse of ground. This is an advantage, as they are readily 

 inspected, and also can be more easily protected from the 

 depredations of herons, kingfishers, etc. A few covers made of 

 rough boards or basket-work may be advantageously used, and a 

 few pieces of wire netting should at any rate be placed over the 

 most exposed portions of the raceways. A little care of this kind 

 will be well repaid. The covers not only serve as protection but 



