io8 BRITISH SPORTING FISHES. 



No member of the migratory or non-migratory 

 Salmonida will spawn either upon mud or sedi- 

 ment. But, unfortunately, they do this sometimes 

 ere the deposit is thrown down. Then what 

 ensues ? Protect the stream as you will from 

 heron, duck, and waterfowl, and from 1,000,000 

 eggs with which the stream is spawned, not more 

 than a very small percentage of fry will come forth. 

 The spawning-beds of rivers must be pure and 

 clean, else no successful hatching can take place. 

 Where solid matter is held in suspension over a 

 spawning-bed the eggs are suffocated, and any few 

 that may escape usually turn out to be deformed 

 fish. This is owing to the clogging of the outer 

 wall of the cell-sac, which interferes with the equal 

 absorption of oxygen from the water. Therefore, 

 where this sort of pollution exists, the absolute 

 extinction of trout is certain at no very distant 

 date. 



Of late years disease has played terrible havoc 

 in some of the best northern streams. In one 

 river I could name, scarcely a fish can be caught 

 which does not show in some way marks left 

 by disease want of tail, partial loss of fins, 

 white patches on the skin, where the fungus has 

 previously grown. That numbers of the fish 

 attacked do survive there can be no question ; 

 and that the disease may be prevented at the cost 

 of a few fish I have but little doubt. In these 



