959 



fourth meeting was held at Prestwick Car, near Ponteland, a space 

 of flat, marshy and boggy land, about two miles across, with a consi- 

 derable pool of rather shallow water, communicating with the little 

 river Pont by a deep ditch, of about one-third water and the remain- 

 ing two-thirds of filthy mud. It is diflScult to account for this flat 

 expanse of bog, marsh, and water. That it has once been more ele- 

 vated is evident, as the stumps of trees, blackened, as is usual in bog- 

 wood, are scattered over its whole surface. "When the lake is low, 

 they may be seen in considerable numbers, just showing themselves 

 above the surface of the water. Two sorts of tree may be distin- 

 guished : a species of fir, probably the common Scotch fir, as the 

 wood when sliced and put under the microscope appears to belong 

 to that plant. The other tree is the common birch ; in this the 

 bark is remaining, in many cases almost quite sound, whilst the 

 wood is soft, or altogether gone ; thus furnishing us with the means 

 of accounting for the fact, that in most of the larger fossil plants of 

 our coal mines, we have the impressions of the bark only, the place 

 of the wood being usually occupied by mud or sand. How the trees 

 at Prestwick Car have got into their present situation it is diflicult to 

 say ; the appearance of the place, an extensive flat, like the bottom 

 of a large dish, rising ground on nearly all sides forming the edge, 

 would suggest the idea of subsidence of the land at this particular 

 spot, more especially as the Car itself is on so low a level, that the 

 waters of the Pont frequently flow into it. As might be expected, 

 numerous water and bog plants are to be met with ; for some it is 

 the only convenient station near Newcastle. In the ditches, as well 

 as in the lake, Callitriche autumnalis and Chara aspera and hispida 

 are abundant. Amongst the other plants may be mentioned Ranun- 

 culus Lingua, Listera cordata, CEnanthe Phellandrium, Triglochin pa- 

 lustre, Alisma ranunculoides, Hippuris vulgaris, Utricularia vulgaris 

 and intermedia, Carex pauciflora, Potamogeton lucens and hete- 

 rophyllus, Anagallis tenella, Parnassia palustris, Nuphar lutea, Eleo- 

 charis multicaulis, Andromeda polifolia, Habenaria bifolia, Gymna- 

 denia conopsea, Pilularia globulifera, Lycopodium Selago and sela- 

 giuoides, and most of the common North-of-England heath and bog 

 plants, both cryptogamic and flowering. Many fresh-water shells 

 are found in the lake and the ditches which run into it, but they do 

 not appear to be so numerous as they were found some years ago. 

 At one time the Car was not preserved, and water-birds were driven 

 away, and the shells on which they fed were abundant, but now that 

 the place is strictly preserved, the birds abound, and the shells ap- 



