April 25, 1901] 



NA TURE 



627 



atomic weight of the metal varies from 220 to 232. — Pheno-a- 

 ketoheptamethylene and its derivatives, by F. S. Kipping and 

 A. E. Hunter. Pheno-a-ketoheptamethylene is obtained by 

 the action of aluminium chloride on phenylvalerlc chloride ; its 

 oxime is reducible to pheno-a aminoheptamethylene, 



CfiH,/ 



CH.,.CH2.CH.. 

 CH{NH..).CHj 



— Note on diphenyldinitroethylene, by J. J. Sudborough. — 

 Para- and ortho-cyanohydroxy-derivatives of pyridine, by 'J. 

 Moir. 



Geological Society, April 3. — Mr. Horace W. Monckton, 

 vice-president, in the chair. — The igneous rocks and associated 

 sedimentary beds of the Tortworth inlier, by Prof. C. Lloyd 

 Morgan, F.R.S. and Mr. S. H. Reynolds. It has long been known 

 that igneous rocks occur in the district under consideration, but 

 opinions are divided as to their intrusive or contemporaneous 

 character. Evidence is here brought forward to show that the 

 igneous rocks form two bands, the lower interbedded with 

 Upper Llandovery strata, and the upper overlain by Wenlock, 

 and that both bands are probably contemporaneous lavas. The 

 microscopic examination of the lower igneous rock shows that it 

 is a basaltic andesite containing plagioclase (acid andesine or 

 oligoclase), pseudomorphs after enstatite, with chloritic and 

 iron-oxide patches. The higher bed sometimes contains fresh 

 augite, and both bands frequently contain rounded grains of 

 quartz. In other examples the felspars appear in three forms, 

 with augite and enstatite, and the rock ranges from an andesite 

 to a porphyritic basalt. The quartz-grains present appear to be 

 xenoliths. The silica-percentage of the rocks on a moisture- 

 free basis varies from 61 to 67, while the specific gravities are 

 from 2 • 74 to 2 "99. 



Linnean Society, April 4.— Mr. C. B. Clarke, F.R.S. , 

 vice-president, in the chair. — The secretary exhibited some 

 British species of plants forwarded by M. Buysman, of Middel- 

 burg, to show the character of a proposed issue to include the 

 whole of the British flora, on which some remarks were made 

 by the chairman and Mr. James Groves. — Mr. W. B. Hemsley, 

 F.R.S., exhibited specimens of Sapium and Hevea (Euphor- 

 biacece) and Castilloa (Artocarpacese), with a view to clear up 

 certain questions concerning the rubber- trees, by examining a 

 large series of plants and seeds forwarded by Mr. Jenman, 

 Government botanist in British Guiana. The genus Hevea 

 included ten or a dozen described species inhabiting eastern 

 tropical South America, but none in the West Indies. Hevea 

 brasiliensis, the source of the true Para rubber, was not very 

 different from Hevea guianensis, which is restricted to French 

 Guiana, the differences between them being shown in the figures 

 given of the floral structure and seeds in Hooker's Icones 

 Plantarum, plates 2570-2577. It was formerly supposed that 

 two species of Hevea might be distinguished in British Guiana, 

 one {Hevea paucifiora) having thin leaves and a hairy ovary, the 

 other thick coriaceous leaves and a glabrous ovary ; but after 

 examining a large number of specimens, Mr. Hemsley had come 

 to the conclusion that the differences were not constant, and 

 that all the specimens exhibited might belong to one species, 

 and merely represented individual variation. The exhibition 

 ■demonstrated the difficulty of determining species of Hevea 

 from imperfect specimens, and especially from seeds alone. — A 

 paper was read by Messrs. W. B. Hemsley and H. H. Pearson 

 on a small collection of dried plants made by Sir Martin 

 Conway in the Bolivian Andes in 1898-99. This collection 

 contained but forty-six species, but these were of special 

 interest from the great height at which they were found, i.e. 

 betweeri 18,000 feet and 18,700 feet above sea-level. The 

 highest Andine plants on record were stated to be Malvastrum 

 fiabellatu?H, Wedd., and a grass, Deyeuxia glacialis, Wedd. — 

 A paper was read by Mr. G. S. West on some British fresK- 

 water Rhizopods and Heliozoa. When collecting freshwater 

 algae in different parts of the country the author had found 

 Rhizopods and Heliozoa in abundance, and had preserved them 

 for future examination. The observations now made related to 

 their habits and structure, and comprised descriptions of peculiar 

 forms of some of the commoner types, as well as remarks on 

 .several little-known species. Half a dozen species were de- 

 «cribed as new, and one {Leptochlamys ampullacea) was referred 

 to a new genus. Two points of special interest were (i) the 

 presence of a perforation at the apex of the shell in some forms 



Na 1643, VOL. 63] 



of Difflugia acuminata, the shell thus possessing two openings : 

 and (2) the possession of certain characters by members of the 

 genus Vampyrella which sharply demarcate them from other 

 Rhizopods. In the latter case, Mr. West had bsen able to 

 observe several of these minute creatures feeding on the cell- 

 contents of a species of Mougeotia. 



Mathematical Society, Thursday, April 11. — Dr. Hobson, 

 F.R.S., president, in the chair. — Mr. A. B. Basset, F.R.S., 

 made a brief communication on the projective properties of 

 cubic and quartic curves. Prof. Love, F.R.S., also made a few 

 remarks on the communication. — A paper by Dr. F. Morley, 

 entitled " Summation of the Series 



2°^r3(a-l-«)/r3(i-|-«)," 



«=o 



was communicated by its title. — Lieut, -Colonel Cunninghim, 

 R.E., announced the factorisation of the algebraic prime factors 

 of 5"- I and of 51"^- i. 

 The first = 



151. 3301. 183794551. 992444 1 4459501, 



and the second = 



2 I 22678325021436 I . 207468970805907721 . 



He has not determined the composition of the three large 

 factors. 



Zoological Society, April 16. — Mr. Howard Saunders, 

 vice-president, in the chair. — A communication was read from Mr. 

 W. L. Distant entitled, " A Revision of the Insects of the Order 

 Rhynchota belonging to the Family Coreidae in the Hope collec- 

 tion at Oxford." It was stated to be supplementary to the paper 

 on the same subject already published in the Proceedings (cf. 

 P.Z.S. 1900, p. 807)— Mr. F. E. Beddard, F.R.S., read a 

 series of notes on earthworms, which comprised (i) an account 

 of some earthworms from eastern tropical Africa in the collection 

 of the British Museum ; (2) a note on the spermatophores of 

 Polytoretttus ; (3) a note on the spermatophores of Stuhlmannia ; 

 (4) remarks on the ovaries, oviducts and spermducts of Sttchl- 

 mannia ; and (5) a contribution to our knowledge of the genus 

 Gordiodrihis. — Mr. F. E. Beddard also read a paper on the 

 anatomy and systematic position of the open-billed stork {Anas- 

 tomits oscitans),'b2ise6. on an examination of a specimen of this 

 bird that had died in the Society's gardens. The author was 

 of opinion that the structural differences between Anastonms and 

 the typical storks were so slight that they did not warrant the 

 placing of this bird in a separate family or subfamily. — A paper 

 was read from Dr. H. Lyster Jameson giving an account of the 

 mother-of-pearl oysters {Margaritiferae). It was based upon a 

 study of the series of these oysters in the British Museum and 

 upon an examination of a large series of marketable mother-of- 

 pearl oysters of various species in the London shell-warehouses, 

 and dealt with the specific identity, geographical distribution, 

 local variation, original name and synonymy of the different 

 members of Margaritifera. The subgenus was divided into two 

 sections, characterised respectively by the absence or presence 

 of rudimentary hinge-teeth. Several new species and local 

 forms were described in this paper. — A communication from 

 Miss Emily M. Sharpe contained a list of the Lepidoptera 

 collected by Mr. Ewart S. Grogan during his expedition from 

 the Cape to Cairo. The names of sixty-six species represented 

 in the collection were enumerated in the paper. Two of these 

 were described as new under the names Amauris grogani and 

 Gnophodes grogani. 



Royal Astronomical Society, April 12. — Prof. Turner 

 read a paper by Mr. H. C. Plummer on a method for mechanic- 

 ally compensating the rotation of the field of a siderostat. Prof. 

 Turner had in a previous paper given the principle of several 

 methods by which this might be effected, but Mr. Plummer's 

 appeared a still simpler arrangement. Prof. Turner gave an 

 account of his own paper — Tables and Formulae for connecting the 

 Co-ordinates of Stars on different Photographic Plates — particu- 

 larly in connection with the Astrographic Chart of the Heavens. 

 — Mr. Bryant read a further investigation on the " two 

 method " personal equation, in which he brought forward many 

 interesting points in connection with the changes in the personal 

 equation of three different observers at the Royal Observatory, 

 Greenwich. — Mr. McClean read a paper on the spectrum cA 

 Nova Persei, and showed photographs, in which its spectruiri 

 was compared with those oin Argfis ancj Nova Nc«n»2e>^ ; J^*th^T 



