Notes and Comments 



67 



NATURE OF DEPOSITS. 



The pre-glacial flora referred to is found in a series of 

 alluvial and estuarine deposits which underlie the boulder-clay, 

 and stretch for nearly fifty miles along the Norfolk and Suffolk 

 coasts, from Sherringham to Pakefield. The deposits consist 

 of estuarine muds and gravels, apparently brought down by 

 the Rhine, which at that period, after receiving numerous 

 large tributaries — now separate rivers — seems to have flowed 

 across the present bed of the North Sea. The plants of our 

 pre-glacial deposits have been co' ,2ted almost exclusively 

 from the alluvium of small tributary channels, not from the 

 alluvium of the main river. The great majority of the species 

 found are the same as those still living, but some exotic species 

 occur, the non-British forms here recorded, are Ranunculus 

 neniorosus, two other species of Ranunculus, one or perhaps 

 two water-lilies, Hypecoum procumhens, Trapa nutans, two 

 species of Viburnum ?, two labiates, a second species of alder, 

 Picea excelsa and Najus minor. 



These give a decidedly pecifliar appearance to the flora, 

 and suggest clim.atic conditions almost identical with those 

 now existing, though slightly warmer. The present list shows 

 the southern element to be more marked than was previously 

 known, and includes in all probability several extinct species. 

 This brings it more into line with the pre-glacial mammals and 

 moUusca, both of which groups contain various extinct formf. 



METHODS OF PRErARATION. 



Many of the seeds are impregnated with pyrites, which 

 tends to decompose and to destroy the specimens. To prevent 

 this, the seeds, after removal from the matrix by washing, are 

 placed, while still wet, on a glass slip, which has been covered 

 by a thin film of paraffin wax. The slip is immediatel}^ warmed 

 from bel(3w, just sufficient to melt the wax. As the moisture 

 evaporates from the upper part of the specimen, the wax is 

 • absorbed from the lower, and the whole seed is impregnated 

 with wax, and rendered tough, and can be easily handled. The 

 superfluous wax may be removed by warm filter paper, or after 

 cooling, the surfaces brushed with benzine. 



PILLOW-LAVA AND SLAG. 



In the discussion on a paper on ' The Origin of the Pillow-Lava 

 near Port Isaac in Cornwall,' by Messrs. C. Reid and Henry 

 Dewey, at the Geological Society recently, Mr. G. Barrow drew 

 .attention to the similarity in mode of arrangement of the 



,1908 March I. 



