HOWIETOUN PLANK PONDS. 161 



liver per diem. With regard to rabbits' livers, they triturate better 

 through the perforated zinc if they have first been plunged for a 

 few seconds into boiling water. In short, with sheep's pluck, cut 

 off the lights, boil the heart, leave the liver raw. Plunge the 

 rabbits' livers." On June 13th (Sunday) I ordered a new plank 

 pond ; and on the 24th it was commenced ; on the 8th of July it was 

 finished, and I began laying a 10-inch spigot and iaucet glazed 

 pipe from the leaf-screen in place of the old 6-inch red tile. To do 

 this I took the water off the old pond from 10 A.M. till 2.30 P.M. 

 The fish showed great symptoms of distress, but only 14 died. 

 On the 1 Oth the fish were much fresher ; no more had died. 

 On the 12th I moved them into the new plank pond, which had a 

 stronger water-supply, I having led an 8 -inch pipe from the new 

 10-inch into the new pond, and only a 6-inch pipe into the old, 

 the reason being that the old plank pond was originally only 16 

 inches deep. It was deepened by planting on a plank the autumn 

 following. The water was at first led into the two plank ponds 

 by spouts from the pipes laid on the ends, and the water fell in a 

 considerable stream, instead of spreading over the inlet screen, 

 and falling as a shower. On the 14th July I noticed the Loch 

 Leven springlings jumping at the inlet screen of the new plank 

 pond, and I have no doubt the jumping accounted for the frayed 

 dorsal fins, more especially as most of the Swiss trout had the 

 dorsal fins frayed last season when they were in the 9-foot 

 plank pond, the inlet screen in which was only 4 inches above the 

 surface of the water. None of the fish in the rearing-boxes were 

 affected. I noticed the fish take advantage of the back-boil of the 

 fall, the current of which is probably nearly equal in velocity and 

 opposite in direction to the falling water. 



