THE NURSERY. 77 



without being carried down with it. The minimum 

 supply for very young fish is less than one would 

 suppose. 



A cold stream throwing one hundred gallons an 

 hour will keep ten thousand alive, with a proper fall 

 and current ; but this minimum should not be resorted 

 to except in cases of necessity. 



If you have a large number of fry to raise in rearing 

 boxes, build a platform where you want the boxes. 



Make all the boxes of the same size.* Place them 

 in a line, side by side, have your distributing-spout 

 just over the upper end of the boxes, and draw the 

 water from it just as you draw the water from the dis- 

 tributing spout in the house into the hatching troughs. 

 This gives uniformity and system, and increases the 

 convenience of feeding and taking care of the fish. 



Place a layer of gravel in each of the boxes in such 

 a way that the water will be deepest under the fall, and 

 the bed of the boxes will slope up towards the outlet. 

 Provide water-plants as freely as you please. Below 

 the system of rearing boxes place a long trap-box, with 

 a screen, which will catch everything that escapes from 

 them by accident. 



Then your arrangement for growing the young fish 

 by this method will be complete. 



If ponds are used, they should be shallow, narrow, 

 very tight, and should be well stocked with water- 



* Four feet long by sixteen inches wide and sixteen inches 

 deep is a good size. 



It is a good plan to widen the outlet and to admit a larger 

 screen, say twenty-eight by sixteen inches. 



