IMPROVEMENT OF FISHERIES 235 



the most favourable. conditions the mortality 1 is 

 great. Fry are usually turned down about three 

 months after hatching, say in April and May. 



Fry are lively little things, about an inch in length. 

 If acclimatised they may be turned into streams 

 after they have been feeding for about a couple of 

 months. In the case of large freshwater lakes, it 

 is advisable to turn in fry at a considerable distance 

 above the outlet, whence they will descend in from 

 eight to eighteen months. One of the secrets of 

 turning down fry is that the streams in which they 

 are to begin the battle of life are suitable to their 

 requirements. The stream, in the first place, 

 should be absolutely without pollution ; it should 

 have a clean, gravel bed, with many little bays and 

 shallows. The fry haunt the pebbly reaches, these 

 affording them the greatest protection. The more 

 thickly grown are the banks with plants and trees, 

 and the stream-margin with brambles and cresses, 

 the better. The first bring food, the second afford 

 protection. About 4 inches of running water is the 

 best depth for fry, and " hides " and " rests " 

 should be inserted for them. These may consist of 

 two bits of brick placed about 4 inches apart, and 

 covered in with a piece of slate. Into these the fry 

 dart when disturbed, and are there safe from their 

 larger enemies. When the fry descend from the 

 streams, they are from 2 to 4 inches in length. 



The deduction is that fry should never be turned 

 into large sheets of water which already contain 

 numbers of predatory fish, not even where the con- 

 ditions appear otherwise favourable. Especially is 

 this true where there are few shallow-water con- 



1 A number of instances are given in the chapter entitled 

 Friends and Enemies of Fisheries. 



