March i, 1888] 



NATURE 



431 



thin shell, or plate of finite curvature. It is proved (i) that only 

 fir an inextensible spherical surface is the potential enerq;yfunc- 

 tion the same function of the changes of principal curvature as 

 for a plane plate ; (2) that in general the shell cannot vibrate in 

 STich a manner that no line on the middle-surface is altered in 

 length, because this condition makes it impossible to satisfy the 

 boundary conditions which hold at a free edge ; (3) that surfaces of 

 uniform curvature with no bounding edges are the only ones 

 which admit of purely normal vibrations ; and (4) that vibrations 

 in which the displacement is purely tangential are possible on all 

 shells whose middle-surfaces are surfaces of revolution bounded 

 by small circles. The possible modes of vibration of the spherical 

 and cylindrical shell receive special discussion. The equilibrium 

 of the shell is also considered. 



Linnean Society, February 2. — Mr. Carrulhers, F.R. S., 

 President, in the chair. — The President called attention to the 

 loss which the Society had sustained by the deaths of Prof. Asa 

 Gray, Prof. Anton De Bary, and Mr. Irwine Boswell (formerly 

 Syme) which had occurred since the date of the last meeting, and 

 gave a brief review of the life and labours of each. — Mr. C. T. 

 Druery exhibited a collection of abnormal British ferns, and made 

 some remarks on the extraordinary number of named varieties 

 which had been recognized, and which now required to be carefully 

 examined and compared, with a view to some systematic arrange- 

 ment of them. A discussion followed, in which the President, 

 Mr. J. G. Baker, F.R. S., Dr. Murie, and others took part.— - 

 Dr. Amadeo exliibited and made some observations on a new 

 species of Taberncvmontana. — A long and interesting pap:;rwas 

 then read by Mr. Henry T. Blanford, F.R.S , on the ferns of 

 Simla, based upon a collection which he had himself made there, 

 " not much below 4500 feet, nor above 10,500 feet." His remarks 

 were illustrated by a map, and by an exhibition of a number of 

 the more noticeable ferns collected, many of which were extremely 

 beautiful. Criticisms were offered by Mr. C. B. Clark, F. R.S., 

 Mr. Gamble (Conservator of Forests Northern Circle Madras) 

 and Dr. William Schlich (Inspector-General of Forests to the 

 Government of India). — A paper was then read by Mr. H. J. 

 Veitch, on the fertilization of Cattleya labiata, var. Mjssice, in 

 which the author detailed an elaborate series of observations under- 

 taken with the object of detecting, if possible, the act of fertiliza- 

 tion of the ovules, to determine the time that elapses between 

 pollination and that event, and to trace the development of the 

 ovules into perfect seeds. After explaining the structure of the 

 sexual apparatus of Cattleya labiata with the aid of drawings 

 showing the separate parts, the processes following pollination 

 were dealt with, first from the development of the rudiment into 

 the perfect ovule, and then the ripening of the ovules into seeds, 

 these processes being also illustrated by drawings made at 

 particular stages. A discussion followed, in which Mr. J. G. 

 Baker, Mr. H. N. Ridley, and others took part, and to their 

 inquiries for further particulars Mr. Veitch replied. — The next 

 paper, by Mr. Joseph S. Baly, contained descriptions of new 

 species of Galerucina, and being of a technical character was 

 taken as read. 



Entomological Society, February i. — Dr. D. Sharp, Presi- 

 dent, in tlie chair. — The President nominated Sir John Lubbock, 

 Bart., M.P., F.R.S., Mr. Osbert Salvin, F'.R.S., and the Right 

 Hon. Lord Walsingham, F.R.S., Vice-Presidents for the session 

 1888 to 1889. —Mr. F. Pascoe exhibited a species of the Hemi- 

 pterous genus Ghilianella, which he found at Para with the young 

 larva. He said it was the only occasion he ever saw the species 

 with the larva, which was new to Mr. Bates. — Dr. Sharp exhibited 

 some insects collected by Mr. A. Carson on Kavalla, an island 

 in Lake Tanganyika. The Coleoptera were nearly all well- 

 known species, exemplifying the fact that many of the commoner 

 insects of tropical Africa have wide distribution there, some of 

 these species being common to both Natal and Senegal. The most 

 remarkable of the insects was a large Lepidopterous caterpillar. — 

 Mr.Champion exhibited specimens of Cajwt'wia^^/mVft, (EdicJtirus 

 nnicolor, Paussusfavieri, Colydium elongattim, Endophlceus spin- 

 ulosus, Hetceinus eirachnoides, Pseudotrec/ius mutilatus, Singilis 

 Incolor, PhyllomorpJia laciniata, recently collected by Mr. J. J. 

 Walker, R.N., at Gibraltar, Tetuan, and Tangier. — Mr. R. South 

 exhibited a remarkable variety of Polyomniatus phlaeas, caught 

 by him in North Devon in 1881. — Mr. R. W. Lloyd exhibited 

 a living specimen of a species of Ocnera from Ispahan. — Mons. 

 A. Wailly exhibited, and read notes on, a number of cocoons of 

 Antkercea assamensis, A. roylei, Actias selene, and Attacus ricini, 

 lately received from Assam ; also a number of nests of cocoons 



of Bomhyx rhadama — the silk of which is used by the Ilovas 

 in the manufacture of their stuffs called " Lam bas "—from 

 Madagascar.— Captain H. J. Elwes read a paper on the 

 butterflies of Sikkim, the result of many years' collecting. 

 He said he had been enabled to complete his observations during 

 the enforced delay at Darjeeling of Mr. Macaulay's Mission to 

 Thibet, of which he was a member. He stated the number of 

 species occurring in this district to be about 530, which is greater 

 than the number hitherto found in any other locality in the Old 

 World. Of these the greater part only occur in the hot valleys at 

 an elevation of 1000 to 3000 feet, and these are for the most part 

 of a purely Malayan character, whilst those found in the middle 

 zone are in many cases peculiar to the Himalayas ; and the few 

 species from the alpine parts of the country at 12,000 to 16,000 

 feet are of a European or North Asiatic type. An important 

 feature in this paper was the numerous observations taken on 

 the habits, variation, seasons of appearance, and range of altitude 

 of the various species, for which the author said he was largely 

 indebted to Herr Otto Moller, of Darjeeling. The paper con- 

 cluded with an analysis of the species and genera compared with 

 those found in the North- West Himalayas and in the Malay 

 Peninsula. Mr. J. H. Leech, Dr. Sharp, Captain Elwes, and 

 others took part in the discussion which ensued. 



Zoological Society, February 7.— Prof. W. H. Flower, 

 F.R.S., President, in the chair. —The Secretary read a report 

 on the additions that had been made to the Society's menagerie 

 during the month of January. — Mr. E. G. Loder exhibited and 

 made remarks on a very large African Elephant's tusk, which 

 weighed 180 pounds, and was, as he believed, the largest tusk 

 hitherto authentically recorded. — Mr. A. Thomson exhibited a 

 living specimen of the larval foi-m of Stick-Insect {Emptisa 

 paupcrata) from the Insect House. — Mr. G. A. Boulenger, read 

 the third of his series of contributions to the herpetology of 

 the Solomon Islands. The collection now described have been 

 obtained by Mr. C. M. Woodford during a visit to the islands 

 of Guadalcanar and New Georgia. The author observed that 

 though the collection contained over 200 specimens, only four 

 species were thereby added to the heqietological list of the 

 Solomons, showing that our knowledge of that fauna was ap- 

 proaching completion. — A communication was read from Mr. 

 Arthur G. Butler, containing descriptions of some new Lepido- 

 ptera from Kilima-njaro. Some of the specimens described 

 had been collected by the late Bishop Hannington, and others 

 by Mr. F. J. Jackson. — Mr. Frank E. Beddard read a paper 

 upon certain points in the visceral anatomy of the Lacertilia, 

 The paper dealt principally with Monitor, in which the presence 

 of a peritoneal fold covering the abdominal viscera and separat- 

 ing them from the lungs was referred to ; this membrane was 

 compared with a corresponding structure in the Crocodilia. — 

 Mr. D. D. Daly gave an account of the Birds'-nests Caves of 

 Northern Borneo, of which no less than fifteen were now known 

 to exist in different parts of the North Bornean Company's 

 territories. Most of these were situated in limestone districts 

 in the interior, but two of them were in snadstone formatit/ns 

 near the sea-coast. — A communication was read from Mr. R. 

 Bowdler Sharpe, containing the description of a new species of 

 Tyrant-bird of the genus Elainea, from the Island of Fernando 

 Noronha. This was proposed to be 'called E. ridleyana, after 

 Mr. H. N. Ridley, who had obtained the specimens during his 

 recent exploration of that island. — Mr. Osbert Salvin, F.R. S. , 

 read a note on Ornithoptera victories, from Guadalcanar Island 

 of the Solomon Group, and pointed out the characters which 

 separated this species from a closely allied form of the Island 

 of Maleite, proposed to be called O. regtnce. 



Geological Society, Februarys.— Prof. J. W. Judd, F.R.S., 

 President, in the chair. — The following communications were 

 read : — On some remains of Sqiiatina cranei, sp. nov., and the 

 mandible of Belonostomus cinctiis, from the Chalk of Sussex, 

 preserved in the collection of Mr. Henry Willett, of the Brighton 

 Museum, by Mr. A. Smith Woodward. — On the history and 

 characters of the genus Septastrcea, D'Orbigny (1849), and the 

 identity of its type species with that of Glyphastrcca, Duncan 

 (1887), by Dr. George Jennings Hinde. — On the examination 

 of insoluble residues obtained from the Carboniferous Limestone 

 at Clifton, by Mr. E. Wethered. 



Royal Microscopical Society, February 8. — Annual 

 Meeting. — The Rev. Dr. Dallinger, F. R.S., President, in the 

 chair. — The Report of the Council was read, showing a further 

 increase in the number of Fellows, and in the revenue of the 



