242 FLY FISHING 



been destroyed either by large gulls or herons, 

 which occasionally visit the place, or by other 

 methods which have not come under my ob- 

 servation, The secret of the breeding of those 

 trout in still water is, I believe, to be found in 

 the fact that there is a very small part of the 

 pool, joined to the rest in ordinary winters, but 

 shut off from open connection with the main 

 body of water in summer. The trout spawn on 

 the stony shallow between the two pieces of 

 water in winter. The ova hatch out, and such 

 of the fry as have taken refuge in the small 

 pool are shut in there, and thus protected from 

 the larger fish when the shallow connection 

 becomes dry in May or June. I have continually 

 found this detached pool, which is only a few 

 yards in length and breadth, full of small trout 

 up to the size of yearlings in summer, and in 

 the following year have noticed a large increase 

 of small fish in the main water. After dry 

 winters, on the other hand, when the shallow has 

 remained dry and the connection with the little 

 pool has never been properly established there 

 has been no increase of small trout. Ova have 

 probably been laid and hatched on ather stony 



