133 PROCEEDINGS Of SOCIETIES. 



cation was read : — " On the Structure of a Fern-stem from the Lower Eocene 

 of Ilcrne Bay, and on its allies, recent and fossil." By W. Carruthers, Esq., 

 F.L.S., F.G.S. The author described the characters of the fossil stem of a 

 Fern obtained by George Dowker, Esq., F.G.S. , from the beach at Heme Bay, 

 and stated that in its structure it agreed most closely with the living Osmunda 

 regalis, and certainly belonged to tlie OsmundacecB. The broken petioles show 

 a single crescentic vascular bundle. The section of the true stem shows a white 

 parencliymatous medulla, a narrow vascular cylinder interrupted by long slender 

 meshes from which the vascular bundles of the petioles spring, and a parenchy- 

 matous cortical layer. The author described the arrangement of these parts 

 in detail, and indicated their agreement with the same parts in Osmnnda regalis. 

 He did not venture to refer the Fern, to which this stem had belonged, posi- 

 tively to the genus Osmunda, but preferred describing it as an Osmundites, 

 under the name of O. Dowkeri. The specimen was silicified, and the author 

 stated that even the starch-grains contained in its cells, and the mycehum of a 

 parasitic Fungus traversing some of them were perfectly represented. Its pre- 

 cise origin was unknown ; it was said to be probably derived from the London 

 clay, or from the beds immediately below. Discussion .- Mr. W. W. Smyth, 

 in calling on those present for remarks on the paper, commented on the very 

 remarkable manner in which the minutest details of the original plant had be- 

 come silicified. Mr. Etheridge mentioned the discovery of fossil Fern-stems 

 of somewhat similar character at Bromsgrove. Professor Eamsay suggested 

 the possibility of the fossil having been derived from a bed even higher than the 

 Tlianct Sands. He thought the rarity of such delicate structures being perfectly 

 preserved by silicification not so great as might at first sight appear, for in Antigua 

 and elsewhere vegetable forms had been converted into flint as completely and 

 distinctly. Mr. Woodward cited the hot springs in the island of St. Michael as 

 converting portions of vegetables still growing into flint. He had heard of the 

 ends of piles being converted into flints in the course of thirty years, but had not 

 yet seen them. Mr. Jenkins inquired whether the Osmundee from different 

 formations offer any evidence of the climate under which they lived. He 

 thought that where vegetable structures were perfectly preserved in flint, the 

 process of silicification had gone on but slowly ; but this fell more within the 

 province of the chemist than of the geologist. Mr. Hulke suggested the pos- 

 sibility of the Fern having contained a certain amount of silica while still 

 living. Professor Morris referred the fossil to the Thanet Sands. He thought 

 that the silica in fossil coniferous and endogenous wood varied in character, 

 and this might throw some light on the process of conversion. He considered 

 tliat objects containing phosphate of lime, and tliose containing carbonate, were 

 subjected to different processes of silicification. Mr. Whitaker was strongly of 

 opinion that the fossil had been derived from quite the upper part of the 

 Thanet Sands. Professor Duncan called attention to the process of silicification 

 as exhibited by the Antiguan corals, in which one highly insoluble mineral had 

 been replaced by another almost as insoluble. Mr. Carruthers, in reply, did not 

 think that anything could be predicated as to climate from extinct species ; if this 

 were attempted, a similar error to that with regard to the climate under 



