How to obtain it. 57 



construction of these protected spawning beds on a fairly 

 extensive scale, they may be divided into sections, and the fish 

 allowed access to the various sections as they spawn in succession. 

 The first fish that come up, for instance, will push forward until 

 further progress is barred by the leaf screen. Finding they 

 cannot get any higher up-stream, and at the same time finding 

 suitable spawning ground, they will deposit their ova, and return 

 to the pond from whence they came. 



Now, by placing a screen or grating below this spawning 

 ground to prevent more fish coming up on to these nests, the 

 later fish are obliged to deposit their eggs lower down, and when 

 the beds are all made use of the fish should not be allowed to 

 enter the stream at all. The latest fish will then spawn in the 

 pond where the stream enters it. It may sometimes happen that 

 a pair of the earliest fish, instead of pushing up-stream, will 

 spawn in a lower reach of the raceway which is wanted for the 

 later fish. Such an occurrence cannot always be avoided, but 

 such a nest can be protected by wire netting from the depreda- 

 tions of the later fish. Or, if observed in time, the fish may be 

 driven off, or netted out and carried higher up-stream. Any one 

 who is determined to carry out the work thoroughly can easily do 

 it ; but in such a case it will require a little attention. It 

 possesses one very satisfactory feature, however, and that is that it 

 will amply repay the amount of care and attention bestowed 

 upon it. 



And now a few words as to the preparation of the spawning 

 ground. By altering the natural course of the stream and making 

 it wind back and forward, a considerable amount of ground may 

 often be made available, and it is well worth while to take some 

 pains with this part of the work. The great point is to make as 

 much available spawning ground as possible. Being beyond all 

 danger of flooding there is no fear of the work being washed up 

 or half destroyed by a spate. 



The stream which is to be made into a spawning race should 

 have an easy gradient, so that the water just ripples along nicely 

 over it, and the bottom should be of gravel. This gravel bed 

 should be from six inches to a foot deep, and should consist of 

 stones, about one third of which may be about the size of walnuts, 



