December 8, 1898J 



NA TURE 



141 



disappears at a lemperalure which is a few degrees below the 

 critical point of carbon dioxide or of some hydrocarbon. The 

 fact that the critical temperature of the liquid is a little below 

 the point corresponding to carbon dioxide, in the case of a 

 mineral containing that substance is not, however, of very 

 great significance as pointing to the presence of a permanent 

 gas. A small quantity of methane would produce the same 

 result (Kuenen, Phil. Mag., 1897). 



Further, although it can be shown that compact minerals do 

 enclose carbon dioxide and hydrocarbons, gases which can 

 easily be liquefied, the analogy cannot be extended to gases 

 such as hydrogen and helium in connection with minerals 

 like chlorite, mica, and clevite, wliich exhibit many cleavages. 



On the other hand, there is, as I have endeavoured to show, 

 a considerable amount of evidence in favour of the theory which 

 I have put forward : — Tliat in the iiiajori/y of cases where a 

 mineral substance evolves gas under the influence of heat, the 

 gas is the product of the decomposition or interaction of its 

 non-gaseous constituents at the moinent of the experiment. 

 The results of such experiments cannot, therefore, serve as 

 basis for speculation as to origin and history of the substances 

 in question. 



Geological Society, November 2. — W. Whitaker, F. R.S., 

 President, in the chair. — Sir A. Geikie drew attention to some 

 specimens im the table which had been collected by the 

 Geological Survey from the Silurian rocks of County Tipperary. 

 These contained impressions that bore a close resemblance to 

 flattened and drawn-out graptolites, and others that might be 

 taken for mollusca or phyllopoda enlarged by cleavage. It 

 seemed to him, however, extremely doubtful whether these 

 forms were truly of organic origin. They were exhibited in the 

 hope that the palaeontologists in the Society might be able to 

 throw some light upon them from the zoological side. — Dr. 

 G. J. llinde exhibited and commented on specimens of 

 Devonian rocks sent by Prof. Edge worth David and Mr. 

 I'iltman from the rail way- sect ion at Tamworth, New South 

 Wales, which had been received since their paper was read. — 

 Note on a conglomerate near Melmerby (Cumberland) by J. K. 

 Marr, F. R.S. In this paper the author describes the occur- 

 rence of a conglomeratic deposit which shows indubitable effects 

 of earth- movement, not only on the included pebbles, but also 

 on the surface of one of the deposits. The rocks are coloured 

 as basement Carboniferous rocks on the Geological Survey map. 

 -Sir A. Geikie remarked that in his opinion the author ha<l 

 completely proved the point sought to be established. The 

 peculiar features of the conglomerate described in the paper 

 were obviously due to earth-movements, and not to glacial 

 action. At the same tiine, while frankly admitting the explana- 

 tion of the case now brought forward, he held that conclusive 

 evidence had been obtained of glacially-striated boulders in old 

 geological deposits. Other speakers supported Dr. Marr's view 

 that the surface-features of the stones exhibited were due, not to 

 glacial action, but to earth-movements. The author, in reply, 

 slated that he had brought the case forward simply as an 

 example which might be appealed lo in future discussions, as 

 showing excejitionally good indications of the various features 

 produced by slickcnsiding. — Geology of the Great Central 

 Railway (New Flxtension to Lond(m of the Manchester, Sheflicld 

 and Lincolnshire Railway) : Rugby to Catesby, by Beeby 

 Thompson. — On the Remains of Amia froin Oligocene Strata 

 in the Isle of Wight, by K. T. Newton, F.R S. 



Entomological Society, November 16. — Mr. R. Trimen, 

 F. K.S., President, in the chair. — Mr. Tutt showed, for Mr. 

 Herbert Williams, a series of specimens of Pararge egcria bred 

 from eggs laid in July. A portion of the brood were forced, 

 and the imagos, which emerged in November and December of 

 the same year, showed marked darkening of the hind margin of 

 the under side of the hind wings, and were of a greyer colour 

 than those which appeared at the normal tiine. He also ex- 

 hibited a batch of fifty siiecimens of .Amphidasys beliilaria bred 

 from ova deposited by a female captured in Essex. The progeny 

 ranged from a colour rather lighter than the normal form to a 

 blackish tint almost equal to that of var. donbledayaria ; all 

 intergrades were represented without sign of discontinuity. — 

 Mr. H. J. Elwes gave an account of a journey undertaken by 

 him in June and July of the present year to the Russian portion 

 of the Altai mountains, partly for sport and partly to investi- 

 gate the distribution of insects in that region, and the line of 

 demarcation between the Eastern and Western I'alaearctic 



NO. 15 19, VOL. 59J 



sub-regions. He exhibited samples of 141 species of butter- 

 flics taken by himself. Of the.se many had not been previously 

 recorded from the region, of which the total number of species 

 now stood at 184 ; his list show-ed that the lepidoplerous fauna 

 had a more European and Siberian character than had been pre- 

 viously supposed, or than Seebohm had found to exist in the 

 avifauna. The number of undescribed species taken was small, 

 but several forms were previously known only from remote 

 localities, such as Melilaca uiiiiia, hitherto recorded from the 

 fells of Lapland. Few Heterocera were take", but among them 

 was the third recorded example of Arclia Ihii/ea, Dalm. — Dr. 

 A. G. Butler communicated a paper on some new species of 

 African Pierinae in the collection of the British Museum, with 

 notes on seasonal forms of Belenois. 



Linnean Society, November 17. — Dr. .\. Giinther, F. R.S., 

 President, in the chair. — Prof. Stewart, F.R.S., exhibited and 

 made remarks on the .skull of a fox that was described and 

 figured by Bateson in his work on variation. Both upper 

 canines had divided crowns. He also exhibited the douiile 

 tusk of an Indian elephant. The tusk was two feet in length, 

 and had a deep groove on its anterior and posterior surfaces. 

 He considered that in both cases the condition was probably 

 due to partial cleavage or grooving of the dental papilla. The 

 I'resident, referring to the exhibition of a r.omewhat similar tusk 

 at the previous meeting, indicated the points in which the two 

 examples differed. — A paper was read by Mr F. Pickard 

 Cambridge on some spiders from Chile and Peru, collected by 

 Dr. Platte of Berlin. The collection was made during a journey 

 extending from Tumbez, in Northern Peru, down the coast of 

 Chile to Cape Horn, and contained nineteen species, of which 

 seven proved to be new to science. — Mr. Spencer f^e M. Moore 

 read a paper entitled "The botanical results of a journey 

 into the interior of Western .\ustralia ; with some observations 

 on the nature and relations of the desert flora, and on the 

 probable origin of the Au.stralian flora as a whole." The 

 author briefly sketched the physical and botanical, features of 

 the West Australian desert, indicating the parallel of 30° S. as, 

 at least in the Coolgardie district, the dividing line between two 

 subfloras. Flowering takes place almost entirely in spring time, 

 when alone the conditions arc favourable to it. Statistics of the 

 desert-flora were then given. These comprise 867 known specie-^, 

 of which S60 are Phanerogams, referable to 319 genera, distri- 

 buted among 73 natural orders. Of the flora 58 per cent, con- 

 sist of species ranged under 8 orders, with Compositac and 

 l.cgiiininosae heading the list, leaving 42 per cent, to be shared 

 between the remaining 65 orders. The author disbelieved the 

 current theory of Scandinavian predominance; and the preva- 

 lence in Eastern Australia of forms of Indo-Malayan facies was 

 held to be due, in great measure, not to immigration, but to 

 descent from the primitive Tertiary flora. Moreover, the 

 balance of exchange between Indo Malaya and Australia in 

 favour of the former area, was considered as coming under the 

 doctrine of chances, and not as implying any inherent superiority 

 of the one flora over the other. While in Europe the ."Vustralian, 

 i.e. the xerophilous, element was, owing to change in climate, 

 eliminated in favour of the present hygrophilous vegetation, in 

 Eastern Australia the conditions remained as they were in 

 earlier Tertiary times until desiccation set in. He held that this 

 desiccation dates from an earlier period in Western Australia ; 

 and that this, together with the isolation of the Western portion 

 of the continent in .Secondary times by a sea, and later by 

 stretches of desert, explains the floristic difference between the 

 two halves of Australia. — -Mr. C. B. Clarke, F. R.S , madesoine 

 observations on the origin of the Australian flora, and on the 

 dispersal northwards of species from the Antarctic. — The Presi- 

 dent made some remarks by way of comparing the botanical 

 statistics mentioned by Mr. Moore with the results obtained by 

 zoologists in Australia, both as regards the character and origin 

 of the fauna. 



Zoological Society, November 29 — W. T. Blanford, 

 K. R.S., Vice-President, in the chair. — .Mr. G. A. Boulenger, 

 F. R.S., exhibited a dancing-stick from New Guinea, to which 

 were attached as ornaments two imperfect skulls of the rare 

 Chelonian Carellochelys insciilpta, a species previously known 

 only from a single specimen in the Australian Museum, Sydney. 

 Mr. Boulenger also exhibited and made remarks upon a large 

 female specimen of a sea-snake, Distira stokesi, which had been 

 caught by Mr. !•'. W. Townsend in Kurrachee Harbour covered 

 with a thick growth of green seaweeds.— -Mr. C. W. Andrews 



