202 THE TROUT 



The very properties which made brook-water 

 unsuitable for egg hatching, are those which will do 

 yeoman service when your hatching-trays have been 

 laid aside for the year, and your attention is turned 

 to rearing. Water, therefore, which contains an 

 abundance of natural food, such as water-shrimps, 

 larvae of insects, water-snails, and other more minute 

 forms of animal life, is the best for rearing-ponds. 



The quantity of natural food which a stream or 

 piece of water will be found to contain depends 

 largely on the nature of the soil which forms the bed, 

 and on the character of the water for supporting the 

 vegetable life on which the insects themselves thrive 

 and multiply. 



In the case of some large natural ponds in the 

 south of England, the conditions are so favourable 

 to the growth of water-insects, Crustacea, &c., that it 

 has been found possible to rear annually a limited 

 number of trout on a commercial scale without the 

 help of artificial feeding. But even in such excep- 

 tional cases the number of trout reared is very small 

 when compared with the number which the same 

 pond could yield if the supply of natural food were 

 supplemented by artificial feeding. 



It is sometimes a good plan, however, if your 

 supply of natural food is deficient, to increase it by 



