466 SALMON AND TROUT. 



or all of his fish whenever he wants them, and this can only 

 be done by constructing a number of ponds. These may be 

 round, or square, or any other shape, according to circumstances, 

 and not larger than an acre in extent, otherwise they are difficult 

 to net, and take too much time in running out. I prefer myself 

 ponds of a quarter to half an acre for the yearlings, as the water 

 can be run off in a few hours, the pond fished, and the water 

 shut back in a day. This extent of surface exposed to the sun 

 and air encourages a greater vegetable and insect growth than 

 does a long narrow pond, and it is less easily ' poached.' 



An additional security is to have the keeper's house close 

 to the water, and also to place obstructions, such as posts orna- 

 mented with tenter-hooks, in the ponds ; poachers cannot afford 

 to run the risk of confiscation or loss of nets more than once. 



All ponds, whether for business purposes or for sport, should 

 be capable of being emptied at any time, and the greater num- 

 ber of a pisciculturist's ponds are of necessity drawn down 

 every season in order to supply the demand for fish, and also 

 to make certain that no fish remain in them. A few fish of 

 half a pound amongst the fry will make all the difference in 

 the number of yearlings found, as I know from bitter ex- 

 perience. One season a few yearlings were left behind in a 

 nursery pond, and on the pond being fished the next season, 

 these had nearly quadrupled their size, but at the expense of 

 thousands of fry. Trout are cannibals, and will, unless provided 

 with plenty of insect food, devour one another as long as there 

 is any great difference in their size. This has been observed in 

 the case of a few fish of only eight weeks old, which had been 

 by accident put in a hatching trough amongst some fry of about 

 five weeks old ; a comparative monster was seen with the tails 

 of two younger fario sticking out of his mouth ; he was instantly 

 captured, and when transferred to a basin in order to exhibit 

 his amiable propensity, he disgorged one of his little cousins, 

 half-digested, but the other disappeared down his throat ! This 

 propensity doubtless increases with age. 



I have in my hatchery, devoted to the different varieties 



