130 Proceedings of the British Association, 



manner as that proposed by M. Goppert. He warned geologists 

 against drawing any inferences from the numerical proportion of 

 plants in different strata, since their preservation would depend more 

 upon the nature of their matrix, the depth of the sea, and other cir- 

 cumstances, particularly the nature of the plants themselves ; for it 

 appeared from Dr. Landless experiment that some plants entirely 

 disappeared in water, whilst others remained for a considerable 

 time. — Mr. C. J. Bunbury said, that too much importance had been 

 attached to Dr. Lindley's experiment ; the preservation of plants in 

 water was stated to depend upon the nature of their tissue and 

 consistency, the more robust plants best resisting decomposition ; yet 

 the JEquisetum hyemale, a plant containing an unusually large propor- 

 tion of silex, disappeared entirely. In this experiment the large and 

 robust ferns were amongst those plants which best resisted the action 

 of water, but in the coal measures many extremely well preserved 

 species resembled in their consistency the recent Trichomanes and 

 Hymenophyllum, which are as delicate and fragile as mosses. Again, 

 it was evident that the plants preserved in the coal measures had not 

 merely been subjected to maceration in water as in Dr. Lindley's ex- 

 periment, but also to pressure, for the largest stems of Sigillaria and 

 Lepidodendron were pressed flat, and it was probable that vegetable 

 matter could not be converted into perfect coal without pressure, 

 otherwise the volatile constituents would have escaped. The propor- 

 tion of fossil plants in each formation must depend on other cir- 

 cumstances besides their power of resisting decomposition, and the 

 experiment required to be made over again, with various modifica- 

 tions. It was a singular circumstance that no mosses had been 

 discovered in the older rocks, and only two species in the tertiary ; 

 for although the terrestrial species employed in Lindley's experiment 

 disappeared entirely, this would scarcely happen to the numerous 

 species which live habitually in water and marshy situations. 



' On the Structure and Relations of Cornulites and other allied 

 Silurian Fossils,' by Mr. J. W. Salter. — The singular fossil named 

 Cornulites serpularius, is well known as characteristic of the Silurian 

 rocks of Gothland, Britain, and North America and its affinities have 

 been the subject of much conjecture. Mr. Salter's investigations 

 proved that it differed essentially from any crinoidal animal or coral, 



