How to obtain it. 175 



feet, barriers may be placed, over which the water ripples from 

 one section of the bed to another. An excellent material for these 

 barriers will be found in ordinary roofing slates. I have used 

 them with success for many years, and they are easily stuck into . 

 the bottom, lowered, or raised, or manipulated in any way that I 

 may be desired, and a lot of them should always be available) 

 where fish culture is carried on. They are the cleanest and 

 simplest articles to make use of for such purposes that I have ever 

 met with. They are cheap, easily cut to any shape, they can be 

 laced together if needful by drilling holes through them, and, 

 apart from accidents, are almost imperishable. 



The depth of water should be about four inches, and the 

 bottom should consist of clean gravel, the grains of which are 

 principally about the size of peas. Amongst this gravel the eggs 

 are to be sown, and a section ten feet long and one foot wide will 

 hold easily about fifteen thousand ova. By making the width 

 eighteen inches, the quantity may be increased to twenty thousand 

 or more. But with such an exceedingly simple contrivance 

 there is no need to crowd the ova, and it is far better to err on 

 the side of having too much space than too little. The water, 

 after doing duty in the hatching bed, passes on and finally re- 

 enters the stream from which it came. Should the width of the 

 bed be increased, it should be borne in mind that a greater water 

 supply is needful. If two-inch tiles be used for a bed one foot 

 wide, then a double set of them will be required for a bed one- 

 and-a-half feet to two feet wide ; or a single course of three-inch 

 tiles will answer the same purpose. 



The ova may be laid on the gravel or mixed with it. This y 

 is a question about which there is a difference of opinion. When ' 

 we consider for a few moments the requirements of the ova, and 

 examine carefully the state of things in a natural trout bed, we 

 shall very soon be in a position to judge which is best. I have 

 seen some thousands of trout nests, and I have invariably observed, 

 that where the eggs are deposited naturally, water is found welling 

 up through the gravel in which they lie buried and often buried 

 deeply. Thus, the necessary conditions for their well-being are 

 provided by nature. The same conditions must be found in 

 artificial beds. The eggs must have the benefit of the continual 



