56 UNPRODUCTIVENESS OF STREAMS. 



sea coast and passed through the brackish water, and 

 arrived, by means of floods, in the upper portions of 

 the river or lake that they are caught by anglers. 

 Nature appears to have endowed them with a certain 

 instinct, which induces them to surmount the greatest 

 obstructions (short of a mill weir of six feet in per- 

 pendicular height) in order to get to the mountain 

 streams that have gravelly beds. For instance, at 

 Maam river, the fish pass through, for twenty-eight 

 miles, a lake, in which they do not spawn, to the foot 

 of a mountain more than 1,000 feet high: in fact, 

 the summit of this mountain at Glenlusk is marked 

 1,436 feet above the sea. The source of the river is 

 a spring, situated near the summit of this mountain, 

 and, in order to get to this, we see large salmon 

 struggle, during a flood, through a violent mountain 

 torrent against a current falling at the rate of 200 

 feet per mile, and actually depositing their ova at ah 

 elevation at least of 1,000 feet above the sea ! Such 

 is the avidity with which they will seek any place 

 suitable for the purpose of reproduction, and this 

 instance appears to me one of the strongest proofs 

 of the absolute necessity of making all rivers accessi- 

 ble, since we find these Maam streams most prolific, 

 as they are stocked with young salmon (i.e., parr) 

 every year. The river itself is too shallow and too 

 precipitous for the parent fish, or any large fish, to 

 remain in it, except during these periodical floods, 

 during which they spawn, and then they retire to the 

 lake for shelter and return to the sea. 



