March lo, 1892] 



NATURE 



453 



brane, it appeared almost certain that grain-feeding animals 

 must possess some provision in their economy for removing, 

 during digestion, the walls of the starch-cells of the interior of 

 the grain, in order that the cell-contents may be accessible to 

 the digestive enzymes of the alimentary canal. This is, how- 

 ever, found to be not the case. The cell-wall is completely 

 dissolved before the grain food enters the small intestine, but 

 the enzyme effecting the dissolution is not secreted by any part 

 of the animal economy, but is pre existent in the grain before 

 ingestion. The comparative abundance of the cytohydrolyst in 

 Ihe various grain foods given to stock is, as will be at once seen, 

 of great importance, bearing as it does on the relative speed of 

 digestion. Thus, oats contain a particularly large proportion of 

 the cytohydrolyst ; this fact throws considerable light on the 

 cause of the high estimation in which oats are held as a food- 

 stuff. — On the influence of oxygen and concentration on fer- 

 mentation, by A. J. Brown. The author describes experiments 

 on the reproductive power of yeast, from which it appears that 

 all fermentable nutritive solutions encourage the increase in 

 number of yeast-cells to some fixed point, beyond which they 

 will not reproduce themselves. It is also shown that if a 

 greater number of cells be introduced into a fermentable solu- 

 tion than the liquid could originally develop, no increase in the 

 number of the cells takes place. As under conditions like these 

 fermentation still proceeds vigorously, a number of disturbing 

 factors which complicate the results obtained under ordinary 

 conditions may be eliminated by using non-multiplying yeast- 

 cells. By experimenting with a fixed number of cells, it is found 

 that the presence of oxygen exercises an accelerating influence 

 on the speed of fermentation by means of yeast. This fact 

 seems irreconcilable with Pasteur's theory of fermentation. 

 The author also finds that the speed of fermentation of sugar is 

 not dependent on the concentration of the solution, but that, in 

 solutions containing between 5 and 20 per cent, of dextrose, 

 approximately the same weight of sugar is fermented in equal 

 times. When the amount of dextrose in the solution reaches 

 30 per cent., fermentation proceeds much more slowly.— Limet- 

 tin, by W. A. Tilden. Limettin, C„Hjo04, is a crystalline 

 substance deposited from the essential oil of the lime. It forms 

 very pale yellow, thin prisms which melt at I47°"5. Dilute 

 solutions exhibit a beautiful violet fluorescence. It yields a 

 dibromo - derivative, CiiHgBro04, a trichloro - compound, 

 C11H7CI3O4, and a dibromochloro-derivative, CnH7Br„C104. 

 Nitric acid converts it into a nitro-derivative, CiiHj,(N02)04. 

 On fusion with potash it yields phloroglucinol and acetic acid. 

 It seems to have the constitution C6H.,(OCH3)2. C3HO2.— The 

 acid action of drawing-papers, by C. Beadle. Prof. Hartley 

 has recently shown that drawing papers possess an acid reaction, 

 and considers the acidity to be due to sulphuric acid left in the 

 fibre after the processes of souring and washing in the manu- 

 facture of the paper. Drawing-papers are sized with gelatin 

 and alum, and it is to this latter substance that the author 

 attributes the acid reaction. The aqueous extract from one of 

 these papers was found to react acid towards litmus solution, but 

 basic towards methyl orange. The apparent acidity of the 

 extract is hence due to the presence of a basic sulphate of 

 alumina. 



Geological Society, February 10.— Sir Archibald Geikie, 

 F.R.S., President, in the chair. — The following communications 

 were read : — The raised beaches, and "head " or rubble drift of 

 the South of England : their relation to the valley drifts and to 

 the Glacial period ; and on a late Post-Glacial submergence, 

 Part I., by Joseph Prestwich, F.R.S. The author remarks 

 that, besides the subaerial, fluviatile, and marine drifts of 

 the south of England, there is another drift which is yet 

 unplaced. This he considers to be connected with the " head " 

 overlying the raised beaches. Of these he describes the dis- 

 tribution, characters, and relations along the south coast. The 

 "head" overlies the beaches, and frequently overlaps them. 

 In the beaches large boulders are found, and marine shells, of 

 which lists for the various localities are given. The "head" 

 frequently shows rough stratification of finer and coarser 

 materials. It contains mammalian bones, land-shells only, and 

 occasionally flint implements. On the coasts of Devon and 

 Cornwall it is separated from the raised beaches by old sand- 

 dunes. In South Wales the beach occurs below the mam- 

 maliferous cave -deposits, whilst material corresponding to the 

 " head " seals up the cave-mouths. The ossiferous breccias of 

 the caves are therefore intermediate in age between the beaches 

 and the " head." The origin of the boulders is discussed, and 



NO. I 167, VOL. 45] 



it is inferred that they have been brought, not from the French 

 coast, nor from a submerged land, but from a north-easterly 

 source by floating ice through the Straits of Dover. The 

 MoUusca of the raised beaches, of which a list of 64 is given, are 

 closely related to forms living in the neighbouring seas. These 

 raised beaches are not of the age of the higher valley -gravels ; 

 but the evidence (especially that yielded by the Somme Valley 

 deposits) points rather to their connection with the lower 

 valley-gravels, and therefore, with the exception of the caves, 

 they represent the latest phase of the Glacial period. After the 

 reading of the paper, the President thought the Fellows were to 

 be congratulated that the father of the Society should still con- 

 tinue to furnish them with such papers as that to which they 

 had listened — so full of careful observation, ranging over so 

 wide an area, and raising so many questions of the greatest 

 interest. They would regret that the author was prevented by 

 illness from being present that evening, but he hoped that he 

 would be able to attend when the second part of the paper was 

 read, and when the full discussion of this wide subject could be 

 entered upon. Dr. Evans concurred in the advisability of post- 

 poning the discussion of the paper until the second part had 

 been read. — The C/^«f//«^zonein theNorth-West Highlands.by 

 B. N. Peach and J. Home. (Communicated by permission of the 

 Director-General of the Geological Survey.) In the stratigraphi- 

 cal portion of this paper brief descriptions are given of certain 

 sections in the Dundonnell Forest, from eight to ten miles 

 north-north-east of Loch Maree, which have yielded fragments 

 of Olenellus. The organisms are embedded in dark blue shales 

 occurring near the top of the " fucoid beds " and towards the 

 base of the " serpulite grit," forming part of the belt of fossili- 

 ferous strata stretching continuously from Loch Eriboll to 

 Strome Ferry — a distance of ninety miles. In the Dundonnell 

 Forest the basal quartzites rest with a marked unconformability 

 on the Torridon Sandstone. There is an unbroken sequence in 

 certain sections from the base of the quartzites either to the 

 " serpulite grit " or to the lowest bands of the Durness lime- 

 stone. At these horizons the strata are truncated by a power- 

 ful thrust, which, at Loch Nid, brings forward a slice of 

 Archaean rocks with the Torridon sandstone and basal quartzite. 

 The strata from the base of the quartzites to the base of the 

 Durness limestone, exposed in the Dundonnell Forest, are 

 compared with their prolongations to the north and south of 

 that region, from which it appears that there is a remarkable 

 persistence of the various subzones identified in Assynt and at 

 Loch Eriboll. But between Little Loch Broom and Loch Kishom 

 dark blue shales near the top of the " fucoid beds " have been 

 observed at various localities, evidently occupying the same 

 horizon as the Olenellus shales in the Dundonnell Forest. The 

 serpulites {Salterella) associated with the trilobites in the 

 "serpulite grit" occur in the basal bands of the overlying lime- 

 stone ; they were found during last season in the brown dolo- 

 mitic shales accompanying the Olenellus shales in the " fucoid 

 beds," and they were formerly detected in the third subzone of 

 the "pipe-rock" in Sutherland. Their appearance on these 

 horizons leads us to cherish the hope that portions of Olenellus 

 may yet be met with in certain shales in the quartzites, and 

 probably in the lowest group of limestone. The evidence now 

 adduced proves (i) that the "fucoid beds" and "serpulite 

 grit " are of Lower Cambrian age, the underlying quartzites 

 forming the sandy base of the system ; (2) that the Torridon 

 Sandstone, which is everywhere separated from the overlying 

 quartzites by a marked unconformability, is pre-Cambrian. 

 The Olenellus which has been discovered is described as a new 

 species {O. Lapivorthi) closely allted to 0. Thompsoni, Hall, 

 from which it differs chiefly in the arrangement of the glabella- 

 furrows, and in the presence of a rudimentary mesial spine at the 

 posterior margin of the carapace. Remains of other species 

 referrable to Olenellus are described, but these are too frag- 

 mentary for exact determination. All are characterized by a 

 reticulate ornamentation similar to that described by Walcott 

 in O. {Mesonaci's) asaphoides, Emmons. The remains consist 

 chiefly of portions of carapaces. The reading of this paper was 

 followed by a discussion, in which Dr. Hicks, Dr. Woodward, 

 the President, Prof. Lapworth, and Mr. Peach took part. 



February 24.— W. H. Hudleston, F.R.S., President, in 

 the chair. — The following communications were read : — The 

 raised beaches, and "head," or rubble-drift, of the South 

 of England : their relation to the valley-drifts and to the 

 Glacial period ; and on a late post-Glacial submergence, Part 

 II., by Joseph Prestwich, F.R.S. The ossiferous deposits^ 



