58 Wet-Fly Fishing 



really begin, till about May-day. Much 

 depends upon the elevation above the sea. 

 The sources of the river, also have a con- 

 siderable effect on the earliness or lateness 

 of any individual trout stream ; for a river 

 which issues from a chain of lochs, deep 

 and cold, is bound to be a later stream, 

 than one which never passes through any 

 such lochs. The action of the sun upon 

 the shallows, is bound to raise the mean 

 temperature of any river, or water ; just as, 

 once raised in this way, the temperature is 

 bound to be lowered if, on its way, it has to 

 flow into and then out of, any long, deep, 

 and cold Highland loch, in which its waters 

 are practically lost. For, doubtless, many 

 of these Highland lochs are partly fed by 

 deep hidden springs of crystal-clear but 

 ice-cold water. 



Other causes are self-evident, namely, 

 where, from the height of the mountains 

 near its source, the snow lies late ; as also 

 the way in which it remains buried in deep 

 corries, seldom reached by the sun's rays. 

 Melting snow always lowers the temperature 

 of a river, and thus retards the " seasons " 

 in any trout stream, under its baleful 

 influence. 



Who would think of comparing one of 



