The Hatching Apparatus. 25 



to the back edge by straps of lead passed round 

 the pipe and turned over the edge ; in wooden 

 boxes by small tenter-hooks. This idea of Mr. 

 Edon is truly valuable. It has been used at the 

 writer's establishment, and found eminently 

 useful. The spout of the bottom trough must 

 be connected by indiarubber pipe, or otherwise, 

 to a waste pipe leading to the drain, and of the 

 same size as the spout. 



In slate troughs, in order to confine the little 

 fish after hatching, a light wooden frame, 

 covered with fine perforated zinc, must be fitted 

 just above the spout of the lowest trough, and 

 also at any other point if desired, so as to 

 separate the various species, if more than one 

 is being hatched in the same apparatus. In 

 wooden troughs the zinc or gauze may be care- 

 fully nailed directly on to the wood, after being 

 pitched ; but must not be fastened flat on to the 

 wood, but curved outwards a little so as not to 

 cause too great a suction or draught of water, or 



