1864.] 



ON PISCICULTURE. 



13^^ 



and three above. The water can thus run evenly throughout the 

 length of the case. 



The hatching-boxes (fig. 2), four of which are placed in each 

 compartment, are constructed as follows: The sides consist of 

 smooth-planed board, two feet long, three inches high, and an inch 

 and a half thick. The bottom is a glass plate, two feet long, and 

 seven inches wide. The ends are of perforated zinc, or brass wire- 

 work, the same height as the sides, which are strengthened by two 

 transverse pieces of wood. x\ll the wood-work should be of well- 

 seasoned material ; and those parts which come in contact with the 

 water should be glazed, as any resinous or pitchy substance in the 

 wood would prove injurious to the ova. I should mention that 

 the first compartment into which the water falls should be furnish- 

 ed with a network lid of zinc wire, which forms the bottom of a 

 framework three or four inches high, so as to prevent the water 

 running into the next compartment except through the holes in 

 the zinc lid. Thus the larvae of destructive insects, worms, &c., 

 will be kept out. The upper end of the case should stand two 



inches higher than the lower end. The water which runs out 

 from the last compartment is prevented running out the whole 

 wudth of the case by means of two pieces of wood, which are fast- 

 ened to the sides, and reach nearly to the middle, and is carried 

 off by a pipe. 



The slimy deposit which comes even from the purest water, and 

 settles on the eggs (it is not detrimental unless there be too much 

 of it), can easily be got rid of by gently moving the boxes, and 

 allowing it to pass through the ends. 



