68 On Stocking. 



should be commenced in February. If it is desired I 

 will be happy to enter fully into the subject in the final 

 report. 



PERCH. 



Perch destroy small yearlings ; large yearlings of four 

 inches and upwards are comparatively safe. The size of 

 the yearling (other things equal), depends on the size of 

 the parent egg. This again depends on the kind, size, 

 age, and nutrition of the spawner. The best S. Leven- 

 ensis eggs at Howietoun count 25,000 to the gallon, 

 while at Loch Leven the average is about 35,000. Small 

 hill burn trout eggs count 50,000 to the gallon, but by 

 selection and careful treatment, the size can be raised to 

 40,000 eggs to the gallon. From these figures it is 

 evident how far careful selection has removed S. Leven- 

 ensis at Howietoun, from Loch Leven trout. If, however, 

 a smaller breed of trout is desired to hold their own 

 against perch the young trout must be retained two 

 season's instead of eight months in the rearing ponds, 

 this multiplies the cost per hundred or per thousand 

 two-and-a-half times. 



NATUKAL FEEDING IN LOCH. 



The trout at present rise very badly, from which I 

 suspect the bottom feeding is good. If this be so (and 

 it is only by a careful examination in summer that 

 amount of bottom feeding can be estimated), the trout 

 will rise freely so soon as the stock of trout is increased 

 slightly out of proportion to the bottom feeding. If the 

 stock is still further increased, both the rate of growth 

 and the average weight of the trout will dimmish. The 

 prudent rate for stocking a piece of water in this part of 

 Scotland, under 300 feet above the sea, is 150 trout 



