5162 Birds. 



Mr. Barron kindly informs me that the Anacharis has been in the 

 lake at Elvaston Castle for more than a dozen years, having been in- 

 troduced into it by the river Derwent, whose waters supply the lake. 

 It was very troublesome for some years, but is now kept under by 

 having the lake laid dry for a few days during a sharp frost, and again 

 during hot dry weather. A hot sun with a drying wind will kill it to 

 the ground, and if the ground or bottom of the lake be tolerably 

 clean then a sharp frost destroys the roots. It is considered rather 

 unfavourable to fish. In the lake at Elvaston it has not flowered. 



At Newark-upon-Trent the Anacharis appears to have attracted at- 

 tention about six years ago ; it was, I believe, first perceptible in the 

 piece of water called " Newark Dyke," which communicates with the 

 Trent. 



The following facts may perhaps interest. During the proper sea- 

 son a considerable number of salmon ascend the river Trent from the 

 sea to spawn, and have been taken, under particular regulations, at 

 Newark, Shardlowe, King's Mills, &c. During the last few years 

 scarcely a salmon has been taken at King's Mills, and the park-keeper 

 of the Hastings family (to whom the fishery belongs) thought that 

 some unfair means must have been resorted to, lower down the river 

 towards the sea, to prevent the salmon from ascending. In August 

 last he went to Newark to examine the weirs and nets, but he found 

 that the fishery laws had not been transgressed : he found, however, 

 that the new weed had accumulated in many parts to so great an ex- 

 tent as to produce a general impression amongst those connected 

 with the different fisheries that it prevented the free ascent of the 

 salmon up the river as in former years. 



It appears that this persevering weed has located itself in rather a 

 singular situation, viz., the water-tank at the Newark Railway Station. 

 The tank is supplied with water from " Newark Dyke," through pipes 

 200 or 300 yards in length, which discharge their contents into a well, 

 from which they are .raised by steam into the tank. The weed has 

 found its way with the water and gained a firm footing on the bottom, 

 and has become very troublesome. When the tank is cleaned out, 

 again comes the pertinacious stranger and speedily covers the bottom, 

 perhaps a foot thick. 



I learn from a Berkshire friend that he first met with this plant near 

 Sonning, three miles from Reading, but has since seen it close to that 

 town, covering the bottoms of the ditches, and in flower. 



In February, 1855, I had the pleasure of presenting the Society of 

 Natural Sciences of the Canton of Vaud with specimens of the Ana- 



