ANACHARIS ALSINASTRUM. 179 



2ft)S. and another about 41bs. in the lower part of the 

 Whitadder. 



Of late years a considerable nuisance and obstruc- 

 tion to angling has arisen in the Whitadder. The 

 Anacliaris Alsinastrum, the weed that has almost 

 choked up the canals of Lincolnshire and others of 

 the midland English counties, first made its appearacce 

 in this kingdom in Dunse Castle loch, where it was 

 discovered about seventeen years ago by the late Dr. 

 George Johnston of Berwick (who was a keen angler 

 as well as an eminent naturalist.) The intruder found 

 its way into the Whitadder, and has established itself 

 in most of the mill-dams, threatening almost to block 

 them up. It seems not to be particular about what 

 sort of root it gets, but spreads with amazing rapidity, 

 until in several places it has almost stretched across 

 the Whitadder. A sprig of it put into a tumbler of 

 water will indeed in a very short time fill the vessel 

 without taking any root at all. Large trout hooked 

 in the neighbourhood of a bed of this weed make a 

 dash into it, and if the angler is fishing with fly, he 

 may be thankful if he recovers his cast, without much 

 regretting the certain loss of the trout. Fortunately 

 the recurring floods help to repress its extension, and 

 it cannot obtain a footing in the streams. In no other 

 Scotch river that we know of has this annoying in- 

 vader presented itself. 



It is stated that, some thirty or forty years ago, 

 salmon freely entered the Whitadder ; but singularly 

 enough, considering how many must pass its mouth, 

 scarcely a specimen of the grown salar ever ventures 

 into it now. Even in the most plentiful seasons, very 



