PROCEEDINGS OF SOCIETIES. 7 



that it clung to them like " scratchweed," and that if they were overtaken by a 

 lump of it, they were likoly to be entangled and dragged by it into deep water. 

 Even the fishermen complained that they could no longer ply their nets so freely as 

 they were wont, and discontinued setting their hook-lines z'.e., lines laid across the 

 river with a series of hooks attached because the " new weed" either carried them 

 away bodily or stripped them of their baits and fish. Lastly, the drainage was 

 seriously impeded. So much for the " behaviour," to adopt the expression of Mr. 

 Marshall's, "of the Anacharis alsinastrum in England." As respected the origin 

 of the specimen exhibited, Mr. Murphy said his son had brought a small piece of 

 it, with other aquatic plants, in 1850, from Trinity College Botanic Gardens. These he 

 planted in a small pond, fed by a spring which issued from the lands of Ballygaggin, 

 and which pond was intended "to contain the aquatic plants of the proposed botanical 

 collection of the School Farm. The Anacharis was forgotten, but in the following 

 summer it appeared, forming a dense tuft, a beautiful object, at the bottom of the 

 pond. It extended itself rapidly, and by the autumn had nearly occupied the 

 whole of the little reservoir, which was then cleared of it 5 but it soon recovered 

 possession, and, at length, overpowered and destroyed all the other aquatics. The 

 overflow of the pond falls into the Bishopstown stream, and there, especially in the 

 still parts of it, as in the bathhouse beneath Mr. Haycroft's nursery, it has esta- 

 blished itself. In the more rapidly-flowing parts it has insinuated itself amongst the 

 stones at the bottom, but does not appear able to master the current. It is not 

 found higher up the stream than the point where the water discharges itself from 

 the pond ; and, fortunately, as this is so near the sea, it cannot, from the locality, 

 extend itself injuriously, as it has done in England. Its introduction into Ireland 

 is also attended with mystery. The Anacharis belongs to the monocotyledonous 

 class, and is dioecious in other words, staminiferous and seed-bearing blossoms are 

 produced on separate plants. The English plants are all female; but not having 

 seen it in flower in Ireland, he was unable to say whether it is male or female, or 

 both. Every bit of it is capable of throwing out roots and forming a distinct plant. 

 Anacharis belongs to the natural family Hydrocharidacea, which includes, amongst 

 numerous others, the interesting Vallisneria spiralis, which, like Anacharis, bears 

 seed and staminiferous flowers on different plants, and concerning which the beau- 

 tiful fiction has been invented of the stamina-bearing flowers ascending to the surface 

 of the water, being separated from their stalks, and floating with the current 

 amongst the style-producing flowers. Being anxious to ascertain its value as 

 manure, he had asked Dr. Blyth to determine the amount of its contained nitrogen 

 and phosphoric acid, and the result, which was much more favourable to it as a 

 manure than he anticipated, was, that in its wet state, as taken from the water, it 

 contained 0.24 per cent, of nitrogen, and, when dried, rather more than 3 per cent. 

 It contained a considerable amount of lime, and a very little phosphoric acid, in 

 the shape of phosphate of iron. The per centage of nitrogen would lead us to 

 expect very beneficial results from its application as manure. Farm-yard manure, 

 as determined by Boussingault, contained, when dried, only 2 per cent, of nitrogen 

 in the wet state, 0.40. The Anacharis, as taken from the water, and merely 

 shaken, contains 90 per cent, of water ; but the farm-yard manure examined by 

 Boussingault contained as much as 80 per cent, of water. The Anacharis, in its 

 moist state, contains, weight for weight, nearly as much nitrogen as the straw of 

 corn in its ordinary dry state ; and a very valuable application of this plant would, 

 therefore, be, should it ever become sufficiently abundant, to use it as a bedding for 

 cattle for which purpose it would become sufficiently dry in a very short time iu 

 fine weather. 



Dr. Porter exhibited a curious growth in the branch of a laburnum tree the 

 lower part of the tree being thin, while the upper part was thick, and threw out 

 several branches. This the learned doctor attributed to damage done to the surface 

 of the branch, and the juice thus obstructed caused the unnatural thickness ob- 

 servable. 



