Drcember 12, 1901J 



NA TURE 



141 



paper closes with a list of the British members of the family 

 Lichadid:e, to show their distribution among the groups and 

 sections. — Some remarks on the meteorological conditions of 

 the Pleistocene epoch, by Dr. Nils Ekholm. The opinion of 

 the author on this subject differs in some important respects 

 from that of Mr. Harmer. He considers the subject under two 

 heads: (l) What are the meteorological conditions necessary 

 and sufficient to produce a permanent ice-sheet such as that of 

 the Great Ice-Age ? (2) What will be the influence of such 

 glaciation on the meteorological conditions, especially on the 

 cyclones and anticyclones, of the ice-covered land and on its 

 neighbourhood ? The snow-line does not correspond with the 

 mean annual isotherm of 32', for Verchojansk in Siberia is not 

 glaciated, whereas the southern point of Greenland is. The 

 former has a winter anticyclone, while the latter is traversed by 

 the central or northern part of cyclones during the whole year. 

 The area of Pleistocene glaciation in America and Europe 

 coincides with the areas now traversed by the most regularly 

 frequented storm-tracks. There seems to have been about the 

 same ditierence between the mean annual temperatures of Europe 

 and North America in the Great Ice-Age as now, and it is 

 generally agreed that a lowering of the present snow-line by 

 1000 metres would give rise to a similar Ice-Age. The hypo- 

 thesis that a glaciation of North America would raise the 

 temperature of Europe, and vice versA, seems to the author 

 physically untenable. The positions and movements of anti- 

 cyclones are not generally ruled by the ground temperature in 

 our latitudes : they are in most cases eddies formed by the air- 

 circulation in general, and in this the greater area and receipt 

 of heat by the equatorial regions must always be a preponder- 

 ating factor. The author considers that the influence of the 

 Glacial Period on atmospheric circulation would probably be 

 similar to that of a cold winter nowadays. The cyclones would be 

 gradually deviated into a more and more southerly track, while 

 an anticyclone would be formed in 'the north, not, however, a 

 stationary one, but travelling like a cyclone, only more slowly 

 and irregularly. The summer must have been cold and stormy, 

 with frequent fogs, somewhat like that of Cape Horn or Ker- 

 guelen Island at the present day. The author considers that 

 Mr. Harmer underrates the effect of insolation and overrates 

 that of the winds. *' The temperature of the summer only is 

 essential for the phenomenon of glaciation." — On the origin of 

 certain concretions in the Lower Coal- Measures, by Mr. H. B. 

 Stocks. In certain of the Lower Coal-Measures of Lancashire 

 and Yorkshire and in the " hard-bed coal," peculiar concretions 

 known as "coal-balls" occur, which have a considerable 

 interest because they contain well-preserved plant-remains. 

 The author's analysis shows that they consist mainly of calcium- 

 carbonate and iron-pyrites, in varying proportions. Carbonate 

 of lime appears to have been introduced by osmosis through 

 the cell-walls ; and that it was introduced in small quantity and 

 under exceptional circumstances appears to be proved by the 

 comparative rarity of the concretions and their presence in this 

 seam of coal only. During the decay of the vegetable matter 

 of which coal is formed, in contact probably also with animal 

 matter, some of the organic matter would pass into solution in 

 water, causing the absorption of the oxygen in solution ; the 

 result of this is that further decay would take place under 

 anaerobic conditions. This, occurring in water containing sul- 

 phates, would give rise to sulphuretted hydrogen and mud 

 blackened by the presence of ferrous sulphide, while carbonates 

 would also be produced. Experiments were tried (i) on the 

 precipitation of carbonate of lime under varying conditions (in 

 presence of organic matter, &c.) ; (2) on the action of salts of 

 lime and of iron on wood ; and (3) on the action of bacteria on 

 solutions containing calcium-sulphate in solution and ferric 

 oxide in the deposit. In the first series carbonate of lime was 

 deposited in spheres : in the second it was found that iron-salts 

 are preservatives but lime-salts are not ; and in the third, black 

 mud largely consisting of ferrous sulphide was produced, while 

 the calcium-sulphate was converted into carbonate. It is con- 

 sidered that these experiments explain the origin of the " coal- 

 balls." 



Linnean Society, November 21. — Prof. S. H. Vines, 

 F.R.S., president, in the chair. — Dr. A. B. Rendle showed 

 specimens of Ruhus aii:tralis, Forster, the New Zealand 

 " lawyer-vine," which had been sent by Mr. F. W. Burbidge 

 from the Trinity College Botanic Gardens, Dublin. The 

 specimens, which comprised three forms, furnished a striking 

 example of variability within the range of a single species. 



NO. 1676, VOL. 65] 



One, the leafy form, bore leaves with three large leaflets some- 

 what prickly on the stalks and midrib, recalling our native 

 blackberry. In an intermediate form the leaflets were much 

 reduced in size, while the stalks were longer and much more 

 prickly. In a third the flat leaf-surface had completely dis- 

 appeared, the leaves now consisting of an elongated stalk 

 bearing long naked midribs, beset, like the leaf-stalks and the 

 stem, with strong, short, recurving prickles, by means of which 

 the plant climbs over surrounding vegetation. Mr. Burbidge 

 states that the three forms are from three distinct plants, reared 

 from seeds sent from New Zealand ; they are said to be per- 

 manent under cultivation. — The president gave some account 

 of his investigation of the proteolytic enzyme of Nepenthes. 

 He began by pointing out that in the higher animals there are 

 two distinct proteolytic enzymes: (i) pepsin, secreted by the 

 stomach ; (2I trypsin, secreted by the pancreas. The action of 

 pepsin upon the more complex proteids (albumin, fibrin, &c. ) is 

 to convert them by hydrolysis into simpler proteids known as 

 peptones ; whereas the action of trypsin is not only to convert 

 these proteids into peptones, but, further, to decompose the 

 peptones into non-proteid nitrogenous substances, such as 

 leucin, tyrosin, cScc. Among these final products of tryptic 

 digestion there is a substance termed tryptophan, which has 

 the property of giving a pink or violet colour on the addition of 

 chlorine-water. Hence this colour-reaction may be used as a 

 means of determining the nature of the digestion to which any 

 proteid may have been submitted. As the result of previous 

 researches upon the nature of the digestion effected by the 

 enzyme of Nepenthes, the president had come to the con- 

 clusion that it was not peptic, as had been supposed, but essen- 

 tially tryptic. This conclusion has recently been called in 

 question by Clautriau (Acad. Roy. de Belgique, 1900), who 

 reasserts the peptic character of the enzyme. By means of the 

 tryptophan-reaction, which is readily given by the products of 

 a Nepenthes digestion, the president has been able to establish 

 the correctness of the view that the enzyme is tryptic. The 

 tryptophan-reaction has also been found to be given by a 

 number of extracts of plants which are known to contain a 

 proteolytic enzyme ; for instance, pineapple-juice, papain, figs, 

 germinating bean-seeds, &c. It seems probable, therefore, that 

 proteolytic digestion in plants is always tryptic— that there is, 

 in fact, no peptic enzyme in plants. But there is this peculiarity 

 about the trypsin of plants, that it has to work in an acid 

 medium. — A paper by Mr. T. F. Cheeseman on the flora of 

 Rarotonga was read on his behalf by Dr. O. Stapf, who also 

 showed some of the more interesting plants collected on the 

 island. 



Entomological Society, November 20. — Mr. G. H. 

 Verrall, vice-president, in the chair. — Mr. A. H. Jones exhibited 

 various Lepidoptera from the Cevennes, including a series of 

 Lycaena doltis , var. vittata, L. daiiton, L. tneleager, Melanargia 

 iapygia, var. ckanlhe, and M. galalea ah. leucoinelas; also a 

 dark form of Thais cerisyi bred from a pupa received from 

 Armenia. He also exhibited a specimen of Vanessa antiopa 

 taken this year at Eltham, and two specimens of Cerastes 

 erythrocephala bred from ova laid by parent molh captured at 

 sallows near Canterbury. — Mr. H. Rowland-Brown exhibited a 

 remarkable var. ol Melilaea didyina, taken at Chateau de la Caze, 

 Tarn, in which the black markings of the under wings were 

 almost entirely absent, and a series of Lycaena dolus, var. 

 vittata, from the Cevennes, with L. admetus, var. rippertii, from 

 Digne, showing the remarkable affinity of the two species, which, 

 however, were never found on the same ground or in the same 

 localities while collecting. — Dr. Chapman exhibited butterflies 

 taken by himself and Mr. G. C. Champion in the Sierra Albar- 

 racin, Spain, last July, practically the same district as that 

 traversed and described by Mrs. Nicholl in her paper in the 

 Society's Transactions for 1897, and not many new butter- 

 flies were added to Mrs. NichoU's list. Z. quercus was taken 

 at Tragacete. Aiigiades sylvamis was taken both at Albarracin 

 and Tragacete. Adopaea actaeoit was met with a Cuenca 

 (Castile), while Adopaea tinea seemed to be more abundant 

 than A. lineola at all stations. L. hylas and its variety nivescens 

 were found on the same ground. The common form of L. 

 corydon seemed to be corydonius or near that variety, while the 

 very large pale form hispana was the commonest at Albarracin, 

 where the corydotiius form was rare. — Mr. L. B. Prout exhibited 

 and commented upon a number of Geometridie also taken by 

 Dr. Chapman and Mr. Champion in Spain. — Mr. F. Merrifield 

 exhibited specimens of Pieris rapae and Pieris ergane from 



