April iS, 1889] 



NA TURE 



599 



fact, is probably the most important outcome of the experiments, 

 since it affords conclusive proof of the inflaence of sym iietry as 

 the determining cause of hit;h melting-point, slight solul)ility, 

 ic, in the case of naphthalene derivatives. — Cunlribulions 10 

 the knowledge of citiic and aconitic acids, by Mr. S. Skinner 

 a:id Dr. S. Kuhemann. 



Entomological Society, April 3.— Mr. F. Du Cane- 

 (.Jodman, F.R.S., Vice- President, in the chair. — Mr. Osbcrt 

 .Salvin, P'. R.S., exhibited specimens of OrnithoUeia Irojatia, 

 S.aud., and O. /"latent, Staud., received fr m Dr. Staudiiiger, 

 and obi;.ined in Palawan, an island between Borneo and the 

 Philippines. He remarked that Oniithoptcra trojana was allied 

 to O. hrojkiana, Wall. — Mr. K. McLachlan, F. K..S., exhil)iied, 

 and made remarks on, seven examples oi .-Eschna borealis, Zett. , 

 a little-known species of European Dragon-flies. He said that 

 ^ouie of ihe specimens were captured by himself at Kannoch, in 

 lune 1865. The others were taken in LuleA, North Sweden, 

 ind the Upper Engadine (5000-6000 feet), in Switzerland. — 

 Mr. W. II. B. Fletcher exhibited specimens of Ag'otis pyro- 

 hila from variou-; localities, including two from Ponland, three 

 from Forres of a smaller and darker form, and a melanic speci- 

 men from Stornoway at first supposed to belong to A. lucernea, 

 imt which, on closer examination, was seen to be referable to 

 this species. He also exhibited serie; of Tripluvna orb. ma from 

 Stornoway and Forres, and 7'. suhsequa from Forres and the 

 New Forest. The specimens of T. siil>sei/tia from Forres were 

 more distinctly and richly marked than those from the New 

 Forest, and were also rather more variable in colour. — Dr. 

 Sharp exhibited specimens of Prociilits goryi, Kaup, found by 

 Mr. Champion in Guatemala, prepared to show the rudimentary 

 wings under the soldered elytra. Dr. Sharp called attention to 

 the existence of a pecu iar articulated papilla at the base of one 

 of the mandibles ; and he also showed seciions of the head of 

 Neleiis mtemiptus displaying this papilla, as well as the articu- 

 lated teeth on the mandibles. — The Rev. Canon Fowler exhibited 

 specimens of Ai^apantliia lincatocolUs, Don, and remarked that 

 they were able to produce a distinct stridul xtion by the m;)vement 

 of the head against the prolhorax, and of the hinder part of the 

 prothorax against the mesothorax. He further remarked that 

 Dr. Chapman had lately informed him that Erirrhitius viacti- 

 latus, F., had the power of stritlulaling strongly developed. — 

 Mr. Edward Saunders exhibited, on behalf of Mc G. A. J. 

 Rothney, in illustration of his paper on Indian Ants, specimens 

 of the following : — Cainponotus co/npressus and fragmenrs of 

 Soknopsis gcminatus de^tro>ed by it ; Cainponolus %^. (?), with a 

 mimicking spider {Salticus sp.) ; Pseuaotnyima bicolor, with its 

 mimicking Salticus, and a new species of Rkinopsis, viz. 

 ruficomis, Cameron, also found with it, and closely resembling 

 its host ; Diacain/na vji^ans ; Holcoinyriiiex tmiicus, with speci- 

 mens of the grain which it stores and"the Chaff which it rejects ; 

 and a species of AphxiiogasUr, widi the pieces of J\Iiinjsa with 

 which it covers its nest. — Mr. G. A. J. Rothney communicated a 

 paper entitled " Notes on Indian Ants." — Mr. Lionel de Niceville 

 communicated a pajier entitled " Notes regarding Delias sanaca, 

 Moore, a Western Himalayan Butterfly." — Captain H. J. Elwes 

 communicated a note in support of the views expressed by Mr. 

 de Niceville in his paper. 



Geological Society, Aprils.— Mr. W. T. B'anford, F.R.S., 

 Pre ident, in the chiir. — The following communications were 

 read : — The el vans and volcanic rocks of Dartmoor, by Mr. R. N. 

 Worth.— The basals of Eugeniacrinidpe, by Mr. F. A. Bather. 

 Although Profs. Beyrich and von Zittel had alluded to certain 

 specimens of Eugcniacrinus as proving, by the course of the 

 axial canals, that in this genus the basals had passed up into 

 the radials, yet the two cliief authorities who subsecpiently 

 discussed the subject practically ignored this argument. M. de 

 I.oriol contented himself with denying any trace of basals, while 

 Dr. P. H. Carpenter maintained that the top stem-joint repre- 

 sciUed a fused basal ring. In a previous paper the author had 

 argued in favour of Prof, von Zitiel's view without convincir)g Dr. 

 Carpenter of its correctness. Such scepticism was, no doubt, 

 warranted by the lack of detailed description and of figures. 

 The object of the present note was to set the matter at rest by 

 describing and figuring certain dorsal cups of Eugeniairintts 

 airyopliyllUus kindly lent to the author by Prof, von Zittel. 

 Owing to the mode of fossilization the canal system is plainly 

 seen. The axial canal passes up into the radial circlet and 

 gradual. y widens ; at a short distance below the floor of the 

 calycal cavity it gives off five interradial branches ; these sojn 



bifurcate, and the adjacent radial branches converge. Before 

 they meet, each radial branch gives off a very .short branch ; 

 this connects the radiil branch with the ring-canal that contained 

 the interradial and intraradial commissures. The evidence of all 

 o her crinoids that have these canals shows that the basals 

 alway- ci main the interradial branches. And in tug.niacrinus, 

 since the interradial branches have their origin in the middle of 

 the radials, the basals must have pa.ssed up in between the 

 radiaU. The President, Mr. P. Sladen, and Dr. Hindetook fart 

 in the discussion which followed the reading of this paper. — Oi> 

 some Polyzoa from the Inferior Oolite of Shipton Gorge, 

 Dorset, by Mr. E. A. Walford. 



Mathematical Society, April 11.— Mr. J. J. Walker,. 

 F.R. S., President, in the chair. --The Secretary read the follow- 

 ing papers :— On the free vibrations of an infinite plaie of homo- 

 geneous isotropic elastic matter, by Lord Rayleigh, F. R.S. — Od 

 the constant faciors of the theta series in the general case p = 2* 

 by Prof. F. Klein. — On the generalized equations of elasticity 

 and their application to the theory of light, by Prof. K. Pearson. 

 — On the reduction of a complex cpiadratic surd to a periodic 

 continued fraction, by Prof. G. B. Mathews. — Construction du 

 centre de courbure de la developpee de contcur apparent d'une 

 surface que Ton projette orthogonalement sur un plan, by Prof. 

 Mannheim. — Mr. Keaipe and the President made short com- 

 munications. 



Berlin. 



Physical Society, March 22.— Prof, du Bois-Reymon<J^ 

 President, in the chair. — Dr. Assmann gave an account of the 

 results he had obtained by a microscopic examination of the 

 structure of rime, hoar-frost, and snow. In opposition to the 

 view most usually held, that the solid condensations of aqueous- 

 vapour from the air are crystalline, he had observe I some years 

 a.(o, during a sojourn in winter on the Brocken, that hoar-frost 

 consists of amorphous frozen drops, which, by their juxtaposition 

 in rows, build up the long needles of which it is composed. He 

 observed the same structure in some rime whicn he had collected 

 from very various objects in December last during a cold which 

 was not at all intense ; in this case also the spicules of ice were 

 composed of amorphous drops of ice frozen together in lines. 

 In one case the li'tle masses of ice which composed the rime 

 were fro/en together into a leaf-like structure. At the same 

 time some small, scattered, and glitteung ice-formations which 

 had been fonne.l in large numbers on the ground were crystalline 

 in structure, consi ting of thicker or thinner six-sided tablets or 

 somewhat elongated prisms. On other occasions he found that 

 the rime was itself conposed of unequally developed crystalline 

 structures, which branched at angles of 60', and thus gave rise 

 to a dendritic formation ; at the same time the hoar-frost was also 

 composed of crystalline structures. He had als > succeeded in 

 forming ice-fl jwers artificially on a pane of glass, and ha 1 satis- 

 fied himself by a microscopic examination of the same that they 

 are always crystalline in structure. The structure of snow was 

 investigated on the snow-garlands which had been described at a 

 meeting of the Meteorological Society, and consisted of amor- 

 j phous gra'Uiles, such as compose the upper suiface of a glacier. 

 Dr. Assmann attributes the formation of rime and of hoar-frost 

 to the existence of over-coole<l drops of water, which suddenly 

 solidify when driven by the wind against the solid substructure o» 

 which they are found. On the other hand, solid transparent ice 

 is formed when water at o^, or some temperature a )ove zero, 

 comes in contact with any solid object whose tempeiature is very 

 low. — Prof. Liebreich exhibited a series of experiments intended 

 to explain the occurrence of the inert layer in chemical reactions. 

 Two years ago he had demonstrated to the Society the chief 

 phenomena of its occurrence, as seen when a solution of sodium 

 carbonate is mixed with chloralhydrate. When this is done the 

 larger part of the mixed fluids very soon becomes milky, owing 

 to the formation of innumerable small drops of chloroform, 

 while at the same time a thin layer on the surface of the flaid 

 remains clear : this clear portion is the inert layer, and is. 

 bounded above by the general meniscus of the mixture and 

 below by a curved surface, whose convexity is turned upwards 

 towards this meniscus. The speaker had, by means of a series 

 of experiments, disposed of the view which had been put for- 

 ward that the inert layer is only a portion of the mixed fluids from 

 which the chloroform had ev.iporated. Of these experiments it 

 may suflSce to mention only one, in which the fluid was poured 

 into a flat, open basin until it projected with a convex surface 

 above the edges of the basin. Notwithstanding the larger 



