VARIOUS PRODUCTIVENESS OF STREAMS. 19 



not so much bed in proportion to its volume of 

 water ; and it is principally the bed of a river 

 which yields the insects and other food upon which 

 trout live. Eivers where the salmon-fry, or par, 

 as they are usually called, are very numerous, are 

 rarely such good trouting-streams as those where 

 there are none, these small fish consuming a large 

 proportion of the food of the river. Placing some 

 obstruction at the mouth of a stream, in order to 

 prevent the migratory species from ascending it, 

 would improve materially the size of the common 

 trout it contains. Gala and Leader Waters are 

 examples of this. At the mouths of these streams 

 there are mill-caulds which salmon cannot get over; 

 consequently there are no par, and the trout are 

 much larger than in any similar tributaries of the 

 Tweed where par are to be found. A proprietor on 

 the Leader has been making a well-meant but inju- 

 dicious attempt to let salmon up, with what success 

 remains to be seen, but in proportion as the salmon 

 get up the trout will diminish in size ; and we think 

 it is not worth while spoiling the tr outing qualifica- 

 tions of such a stream as the Leader in order to 

 secure a few ill-conditioned salmon in the end of 

 the season. Clean fish will never ascend so small 

 a stream, and it will afford encouragement to some 

 idle vagabonds to poach in winter. 



The trout is unquestionably a voracious feeder, 

 and when hungry is not at all particular as to what 

 it satisfies its appetite upon. Mies and aquatic 



