AMATEUR FISH CULTURE 



some perforated zinc hatching trays. These 

 should be 1J inches deep. They are very easily 

 made, and the ova hatch out well in them. 

 Though ova sometimes hatch out very success- 

 fully even when piled up in two or three 

 layers, it is safer to have them in a single layer. 

 The trays should be suspended in the boxes, and 

 the boxes in the ponds close to the inlets, so that 

 a good current of water may flow through them. 

 The bottom of the boxes should be covered with a 

 thick layer of gravel, but the trays are to be used 

 without gravel. It is advisable to have as much 

 grass as possible round the ponds, and such trees 

 as willows and alders should also be planted 

 round them. Willows and alder sticks planted 

 in the early part of the year come into leaf in 

 the same spring, and afford shade to the young 

 fish in the summer. Some suitable weeds should 

 also be grown in the rearing ponds. Water-cress, 

 water-celery, water-lobelia, starwort, and water- 

 milfoil, are all good. They should be arranged, 

 however, so as to prevent as much as possible the 

 little fish finding hiding places, and it is for this 

 reason also that I have recommended slightly 

 sloping banks when the sides of the ponds are 

 not made of cement. The weeds should be 



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