2 Weiss, Submerged Vegetation of Lake Windermere. 



out, if possible, what measures might be employed to 

 keep it down and so restore the fishing prospects of this 

 popular sheet of water. For the final solution of the 

 problem, the plants in question will have to be carefully 

 studied at different periods of the >'ear, and for several 

 seasons, to see what the effect of certain preventative 

 measures may be, but as a preliminary examination of the 

 lake and its submerged vegetation undertaken during last 

 summer and autumn has suggested a remedy, it seemed 

 well to publish a preliminary account so that the author- 

 ities concerned in maintaining the fisheries might be 

 induced to revert to certain practices, which in the past 

 have been effective in keeping the submerged vegetation 

 in check. 



In October last I visited together with Mr. Nicholson 

 a number of the affected portions of Lake Windermere. 

 An examination of the submerged vegetation at the 

 north end of Parson Bay, about 50 feet from the shore 

 and in 12 feet of water, showed that the bottom of this 

 bay was covered with a dense matted growth of Nitella 

 opaca some 18 inches in height, while above it spread 

 long straggling shoots of the Canadian Pondweed Elodea 

 canadensis. When visited in the autumn the Nitella was 

 dying down forming a black foetid mass, while on the 

 long rapidly grown summer shoots of Elodea, were the 

 numerous short dense autumn branches destined to repro- 

 duce this plant in the next season. 



Nearer the centre of Parson Bay, where the overflow 

 from the sewage works falls into the lake, the vegetation 

 was particularly luxuriant. About 20 feet from the bank 

 and in 6 feet of water, the Water-Milfoil Myriophylluvi 

 was very plentiful, coming up to the surface of the water, 

 while below it was a stratum of Elodea, and below that 

 again the dense growth of Nitella. It would be quite 



