36 FISH CULTURE. 



with coarse gravel, of the size of gooseberries, and 

 some larger, even to the size of plums ; for the more 

 irregular their shape the better, as there will be the 

 more interstices between them, in which the ova 

 can be hidden, and the little fish when hatched can 

 creep for safety. The gravel was at a level of about 

 an inch below the cut which admitted the water, an 

 inch depth of water being quite sufficient to cover 

 them. Each box was furnished with a lid comprising 

 a wooden frame-work, and a perforated zinc centre. 

 This lid was made to fit closely by means of list 

 being nailed on all round. It was padlocked down, 

 to keep out inquisitive eyes and fingers. Boxes in ex- 

 posed places should always be covered in, if not with 

 coarsely perforated zinc, yet with fine wire netting, or 

 water mice will get in, and various birds, as moor-hens 

 and clab-chicks, will pick out the spawn, while a king- 

 fisher, should he discover them, will carry off the 

 fry by wholesale. The stream was then turned on, 

 and flowed steadily from box to box throughout the 

 boxes, and finally discharged itself by the end shoot 

 into the bed of the rill. It need not be imagined 

 that a fall stream of water is necessary, for a small 

 amount of water is sufficient. Indeed, a flow of 

 water, say through a half-inch pipe, would be enough, 

 perhaps, though it is advisable, while the ova are 



