4o6 



NATURE 



[February 23, 1899 



stated, almost indistinguishable from typical /onuerae. Mr. 

 Tutt next exhibited some remarkable colour-aberrations of 

 AnthrKtra filipendiilaCy captured by Mr. VV. II. llarwood near 

 Colchester. — Mr. A. II. Jones exhibited a fine specimen of 

 Sphaeria robertsi 3.W&c\iZ& to the larva of Chaiagia rireseeiis. — 

 Mr. Percy T. Lathy communicated " A monograph of the 

 genus Calisto" ; and the Rev. V. D. Morice, papers entitled 

 " Illustrations of specific characters in the armature and ulti- 

 mate ventral segments of Andrena ,j," and " Notes on Andrena 

 /araxdii, (liraud." 



Geological Society, February i.— W. WhilaUcr, K.R.S., 

 President, in the chair. -On radiolaria in chert from Chypon's 

 Kami, .Mullion District (Cornwall), by Dr. (J. J. Ilinde, K. R.S. 

 This paper describes the discovery of a bed of chert on the 

 mainland, similar to that already described from Mullion 

 Island. The chert is interbedded with clay-slates, and it is a 

 dark massive rock much traversed by (|uartz-veins ; in some 

 parts of it the radiolaria arc preserved in an unusually perfect 

 condition, .showing their latticed structure and spines very dis- 

 tinctly. The radiolaria for the most part are casts only, with- 

 out any definite bounding-walls, their outlines being indicated 

 by the dark material of the groundmass, while the interior of 

 the test has been infilled with clear silica, sometimes the crypto- 

 crystalline variety, at others fibrous chalcedony. In the forms 

 showing the structural details, these alone have been replaced 

 by the opaque subslance, and are thus clearly defined against 

 the clear .silica infilling the test. Eleven species are described, 

 of which ten are new, while one has been previously recognised 

 in the cherts of New South Wales. [At this point. Prof. 

 Bonney took the chair.]— Gravel at Moreton-in-the-Marsh 

 (Gloucestcr.shire), by S. S. Buckman. The author describes 

 certain gravels of Triassic debris and flints at Moreton-in-the- 

 Marsh, with special reference to an upper bed wherein the frag- 

 ments are mostly in a vertical position, some of them having 

 their heavier ends uppermost. He theorises that the vertical 

 materials were the droppings from melting ice floating down a 

 large river.— On the occurrence of pebbles of schorl-rock from 

 the south-west of England in the drift-deposits of southern and 

 eastern England, by A. E. Salter. A set of twelve repre.senta- 

 tive specimens, consisting essentially of (|uarlz and tourmaline, 

 have been looked over by Prof. Bonney, who informs the author 

 that they consist mainly of felspathic grits, schorl-rock, &c., 

 similar rocks to which occur in the south-west of England. 

 The most we.sterly point at which the pebbles have been de- 

 tected is on Great and Little Ilaldon Hills, 800 feet above 

 Ordnance datum, where they are of larger size, more abundant, 

 and coarser-grained than elsewhere. Thence they are traced to 

 the north and .south sides of the Thames Basin, and into East 

 Anglia at VValton-on-the-Na/,c, Aldeburgh, &c. There is a 

 general decrease in height in the deposit in which the pebbles 

 occur, in passing from west to east, and the pebbles appear to 

 have taken two main courses— one along a peneplain west to 

 east from Dartmoor, the other from south-west to north-east 

 across England. The pebbles are ab.sent from the Weald and 

 from the district around Bagshot, from the Hampshire Basin 

 and its bounding hills (with the exception of the extreme south), 

 and from the highest and presumably oldest gravels north of 

 the Thames. 



Linnean Society, February 2.— Dr. A. Gtlnther, F.R.S., 

 President, in the chair.— Mr. E. M. Holmes exhibited speci- 

 mens of Sihiiiimelia oUifera, a native of Venezuela, the wood of 

 which yields an e.s,sential oil known in commerce as " West 

 Indian Oil of Sandal-wood." The plant, hitherto undescribed, 

 was found to belong to a new genus of A'iilaceai\ and has been 

 named Sihimmelia, after the German expert who distilled the 

 oil, and, with considerable difficulty, procured flowering and 

 fruiting specimens of the plant to enable its proper determination. 

 — Prof. Howes exhibited three living specimens of the Lizard 

 llatleria, hatched frcjm eggs which had been received from Prof. 

 Dendy, of Canterbury College, Clirisichurch, New Zealand, with 

 a view of working out the dcvelupiMenl of the skeleton. Prof. 

 Howes described the circumstances under which they had been 

 reared, for the first time in Euiope, and made some observations 

 on the rupture of the egg-shell. Further remarks were made 

 by the Presidcnt.—On behalf of Mr. [. Hamilton Leigh, there 

 was exhibited an unskinned example of the Wild Cat, Felis calus, 

 which had been trapped on January 31 in Argyllshire, and for- 

 warded to London for preservation. It had all the characteristic 

 features of Felis (atiis, and was of great si/e, weighing nearly 

 eleven pounds. The President, in commenting upon the occur- 



NO. 1530, VOL. 59] 



rencc, expressed regret that the rarer .Mammalia of (Jrcat 

 Britain were ilaily becoming .still more rare for want of that 

 protection which might be accorded to them as well as to birds. 

 — Mr. E. S. Salmon read a paper entitled " Notes on the genus 

 Nanomilrium, Lindb." This genus had hitherto been regarded 

 as cleislocarpous. Examination of fresh specimens of N. lenerutii 

 showed, however, that the capsules po.s.sessed a distinct zone of 

 specialised cells —delicate, narrow, and transversely elongated — 

 clearly marking off the upper part of the capsule as a lid. The 

 author pointed out that the characters by which Nanomitriuiii 

 had been separated from Ephemeriim were insulticient, and con- 

 sidered that the former genus should be limited to N. tenerum, 

 N. Aiis/ini, and N. synoiciim, referring A', nicgalosporum (and 

 perhaps also N. aeqiiinocliaU) to Ephemeruin. The essential 

 character of the genus Nanomitrium was the presence of a zone 

 of differentiated cells, by which a regular dehiscence is effected. 

 — Mr. F. W. Stansfield read a paper " On the Production of 

 Apospory by Environment in Athyritini Filix-foemina, var. 

 titicong/omcraliim, an apparently barren Fern." This had been 

 effected by cutting off parts of the immature fronds and allowing 

 them to expand during eighteen months in an uniformly humid 

 atmosphere. The result was the production in the ultimate 

 divisions of a merislematic tissue which gave rise to {i) gemmae 

 or bulbils, (2) prothalli, producing both apogamous buds and 

 ordinary sexual axes of growth. One of the prothalli had been 

 examined, and found to bear both archegonia and antheridia. 

 On layering the primary fronds produced by apo.spory, it was 

 found that these readily gave rise to fresh aposporous growths. 

 The ease with which apospory was induced in the primary 

 fronds, as compared with the extreme diflicully in the case of 

 fronds from an older plant, was said to be characteristic 

 of aposporous ferns in general, Mr. Stansfield having observed 

 it in every case (eight in all) in which he had raised ferns by 

 apospory. Assuming the truth of the " recapitulation" theory, 

 he suggested that this fact indicated that apospory was an atavic 

 trait in ferns. — Mr. H. .M. Bernard g.ave an abstr.act of a paper 

 entitled '■ Recent Poritidae and the position of the Family in the 

 Madreporarian System." In attempting to solve the question 

 as to the affinities of the Poritidae, the author adduced reasons 

 for believing that the skeletal formation of Poriles might be 

 accounted for on the assumption that some early Madreporaria 

 acquired the habit of budding before the skeleton was mature. 

 The paper further dealt with all the recent genera which had 

 from time to time been classed with I'orites, and a revision of the 

 Family was suggested. 



Mathematical Society, February 9. — Lieut. -Colonel Cun- 

 ningham, R.E., Vice-President, in the chair. — Mr. A. Berry 

 communicated a note on a case of divisibility of a function of 

 two variables by another function. — Mr. Love, F.R.S., read a 

 paper on the scattering of electric waves by an insulating sphere. 

 A complete .solution is given of the problem i>f difiermming the 

 disturbance of a train of plane polarised wives of electric force 

 by a dielectric sphere of any size, and with any ditVerence be- 

 tween the dielectric constants of the material of the sphere and 

 the medium outside it. This solution verifies the first approxi- 

 mation for a very small sphere otherwise obtained by Lord 

 Rayleigh, according to which the direction in which the dis- 

 turbance in the scattered wave vanishes is at right angles to 

 the direction of propagation of the incident waves. It also 

 shows that in a second approximation, whatever the difference 

 of dielectric constants may be, the direction in which the dis- 

 turbance in the scattered wave vani.shes is inclined at a slightly 

 obtuse angle to the direction of propagation of the incident 

 waves. Prof. Lamb, F.R.S., and Dr. J. Larmor, F.R.S., 

 spoke on the subject. — Mr. A. E. Western gave an account 

 of his paper on groups of order /'</• *■"' ^Iso communicated a 

 paper, by Dr. L. E. Dickson, entitled " The group of linear 

 homogeneous substitutions on «;</ variables which is defined 

 by a certain invariant." — Mr. A. Young re.id a paper on the 

 irreducible concomitants of any number ot binary quartics. — 

 The following were communicated in absir.ict : On a certain 

 minimal surface and on a solution of V"\ — o, by Mr. T. J. 

 Bromwich. In the first part, the author investigates the con- 

 dition that the plane Ix ■\- my + u: ~ p should envelope a 



minimal surface. This is found to be \ i ,-X -f. = o, 



of- am' an 

 a result previously given by Prof. Genese (Qiiarlerly Journal 

 of Mathemalits, 1S75). The known surfaces of the heli<,oid 

 and catenoid are proved to be deducible from this result. Com- 

 paring this with an expression for / in terms of /, vi, 11 given 



