FISH-CULTURE. 275 



November 13th. In Box v., on the contrary, which was in the 

 warmest situation, and at least a week more advanced, partly on 

 account of temperature, and partly on account of eggs being taken 

 three days earlier (November 10th), there were only about 100 

 eggs killed. As there were about 20,000 eggs in each box. 

 the loss represented 5 per cent, in the one case, and a half per 

 cent, in the other. If we apply the table of percentage of incu- 

 bation, page 206, and suppose it applies equally below 40 F., 

 as between 40 and 50 F., the extraordinary deduction occurs, that 

 the temperature of the water averaged 28 F., which is absurd. 

 There must, therefore, be some point probably between 33 and 

 34 where incubation almost, if not absolutely, ceases, and it would 

 be very interesting to determine the exact percentage of incuba- 

 tion per diem between 33 and 35. Unfortunately, the tempera- 

 tures of the water for this season at Howietoun were not kept. 



The fontinalis eggs commenced to hatch on the 17th January, 

 but not more than 2000 had hatched up to January 29th. 

 On that day I put down the remaining 8000 to hatch, and by 

 the morning of the 31st they were nearly all hatched out. The 

 alevins were dark, firm, and their yolk-sacs were well-shaped, but 

 very sluggish, the temperature of the water being only 36 F. 



By the 8th February the frost had entirely gone, and both the 

 streams at Middlethird and at Howietoun were in flood. The leaf- 

 screen at Middlethird gave way under the spate, as did the inlet- 

 screen of the 60-feet wooden pond at Howietoun ; and the inlet- 

 screen of the upper earth pond at Craigend was torn completely 

 off its hinges, and many fish escaped up the supply-pipe. A leak 

 also sprang alongside the outlet- pipe of the lower earth pond at 

 Craigend, and some 30 yearlings escaped. Similar disasters will 

 always occur to young fish-culturists, but after a little experi- 

 ence, the risk of re-occurrence may be reduced to infinitesimal 

 proportions. Misfortunes in fish-culture seldom come alone, and 

 on the same day I found that most of the eggs in the deep 

 hatching-trays had died. 



I packed and sold 31,000 Lochleven eggs, and sold 1250 year- 

 lings this season, which was the first return made by the Fishery, 



