1 66 



NATURE 



[December 17, 1891 



cherrina, a South European mite, by Mr. A. D. Michael. — 

 Photographs and drawings illustrating the absorpti )n of the 

 tubercle and other bacilli by the leucocytes, phitographs of 

 micro organisms in dental caries, by Mr. J. H. Mummery. — 

 Exhibition of natural history objects with the projection micro- 

 scope, monochromatic light apparatus for microscopic work, by 

 Messrs. E. M. Nelson and C. L. Curties. — Phagocytes inclosing 

 tubercle-effusion from dorsal lymph-sac of frog, by Mr. Pound. 

 — Cherryfield rhomboides in balsam, with a new ^.j apochromatic 

 homogeneous immersion i'4 N.A., by Messrs. Powell and 

 Lealand. — A collection of different species of Rotifera, by Mr. 

 C. Rousselet. — Photograph of a new apparatus for measuring 

 drawings made with the camera lucida, by Sir Walter Sendall, 

 K.C.M.G. — Petrological slides, transparencies of rock sections, 

 Foraminifera, &c., by Mr. G. F. Smith. — Starch from potato 

 fruit under \ inch, with polariscope, by Mr. W. T. Suffolk. — 

 Photographs of PoJtira scales, by the Hon. J. G. Vereker. — 

 Section of passion-flower, by Mr. J. J. Vezey. — Blight of grape 

 vine [Phylloxera) ; Bacillus ;«a//^z (glanders) ; Pacinian corpuscles 

 in mesentery of cat, chlorophyll of moss, Diatomacese from 

 Jutland, a slide containing loo species of Pleurosigma, by 

 Messrs. Watson. 



Entomological Society, December 2. — The Right Hon. 

 Lord Walsingham, F.R. S., Vice-President, in the chair. — 

 Dr. D. Sharp, F. R.S., exhibited and commented on a number 

 of photographs of various species of Lucanidce belonging to M. 

 Rene Oberthiir. — Mr. C. G Barrett exhibited specimens of 

 local forms and varieties of Lepidoptera, taken by Mr. Percy 

 Russ near Sligo, including Pieris napi, var. ne^r bryoiiia; ; 

 Anthocharis cardamines (male), with the orange blotch edged 

 with yellow, and yellowish forms of the female of the same spe- 

 cies ; very blue forms of Polyommatiis alsus ; males of P. alexis, 

 with the hind margin of the under wings spotted with black, and 

 very handsome forms of the female. — The Rev. S. St. John ex- 

 hibited two specimens oiLycana argiades, taken in Somersetshire 

 by Dr. Marsh in 1884 ; three specimens of Deilephila euphorbice, 

 bred from larvse found feeding on Euphorbia paralias on the 

 Cornish coast in September, 1889 ; and a series of various forms 

 of Anchocelis pistacina, all taken in a garden at Arundel. Lord 

 Walsingham, F.R. S., Mr. Barrett, and Mr. McLachlan, 

 F. R. S., took part in the discussion which en ued. — Mr. Jenner- 

 Weir exhibited and made remarks on two dark specimens of 

 Zygcena miiios which had been caught in Carnarvonshire. He 

 remarked that the specimens were not representatives of com- 

 plete melanism, and suggested that the word " ph£ieism " — from 

 (paios, dusky — would be a correct word to apply to this and 

 similar departures from the normal coloration of a species. — 

 Mr. C. J. Gahan exhibited specimens of the common " book- 

 \o\ise," Afropos pulsatoria, Fabr., which he had heard making 

 a ticking noise similar to that made by the "death-watch" 

 {Anobium). — Mr. B. A. Bower exhibited the following rare 

 species of Micro-Lepidoptera : Spilonota pauperana, Frol. ; 

 Gelechia osseella, Stn. ; Chrysoclysta hiniaculella. Haw. ; and 

 Elachista cingilella, Fisch.— Mr. R. Adkin exhibited a variety 

 of Anthocharis cardatnines, and one specimen of Scsia 

 scoliaforinis bred from a larva found at Rannoch. — Mr. G. T. 

 Baker read a paper entitled "Notes on Lyccrna (recte Thecla) 

 rhymnits, tengstrcemii, s.r\6. pretiosa." A discussion followed, 

 in which Lord Walsingham, Captain Elwes, and Mr. Baker took 

 part. — Mr. F. Merrifield read a paper entitled "The effects of 

 artificial temperature on the colouring of Vanessa urticce and 

 certain other species of Lepidoptera." The author stated that 

 both broods of all three species oi Selenia, Platypteryx falcataria, 

 Vanessa urticce, Bombyx quercus and var. callunce, and Chelonia 

 caja w^ere affected by temperature in the pupal stage, the lower 

 temperature generally producing the greater intensity and 

 darkness of colour ; some of the Vanessa urticcB made a near 

 approach to the var. polaris of Northern Europe. A long discus- 

 sion ensued, in which Mr. E. B. Poulton, F.R.S., Prof. 

 Meldola, F.R.S., Mr. Barrett, Mr. Jenner-Weir, and Lord 

 Walsingham took part. — Mr. W. Bateson read a paper entitled 

 "On the variation in the colour of the cocoons of Eriogaster 

 lanestris and Satitrnia carpini," and exhibited a large number 

 of specimens in illustration of the paper. Lord Walsingham 

 congratulated Mr. Bateson on his paper, and on the intelligent 

 care and method shown in his experiments, and said that he was 

 glad to see that at Cambridge there was an entomologist ready 

 to enter this interesting field of investigation, and perhaps at 

 some future day to contest the palm with" Mr. Poulton as re- 



NO. I 155, VOL. 45] 



presenting the sister University of Oxford. He had noticed that 

 the larvae of .S'. carpini, if left in a box with dead food, and 

 probably paitially starved, made a light-coloured cocoon ; but 

 that when the cocoon was made under natural conditions, on 

 living food-plants on the moors, it was of a dark colour. Mr. 

 Poulton and Prof. Meldola continued the discussion. 



Linnean Society, December 3.— Prof. Stewart, President, 

 in the chair. — The President announced the recent bequest by 

 the late Sir George MacLeay, K.C.M.G., of a marble bust of 

 his father, the late Dr. William Sharp MacLeay, formerly a 

 Fellow and Vice-President of the Society. — The President then 

 exhibited a series of specimens of a South American beetle, 

 showing the extremes of variation of colour observable within 

 the limits of a single species. — Mr. J. E. Harting exhibited a 

 photograph of an abnormally situated nest of the chimney 

 swallow {Hirundo rusticd), which had been built for the second 

 time on a swinging hook in an outhouse ; and made some 

 remarks on three recorded cases of swallows nesting in trees, a 

 most unusual habit. — The Botanical Secretary read a paper by 

 Mr. W. West, on the Fresh-water Algse of the West of Ireland, 

 and exhibited by way of illustration a number of preparations 

 under the microscope, and a series of beautiful drawings by the 

 author. The paper was criticized by Messrs. A. W. Bennett 

 and E. M, Holmes, both of whom testified to the excellence of 

 the work done and the value of the drawings. — The Zoological 

 Secretary next read a paper by Dr. W. H. Strachan, on the tick 

 pest of Jamaica, which was characterized as of so serious a 

 nature as to demand investigation by entomologists, with a 

 vitw to a remedy. An interesting discussion followed, in which 

 Mr. D. Morris gave a variety of details from personal experience 

 during a residence of some years in Jamaica, and Mr. A. D. 

 Michael pointed out the generic characters of certain West 

 Indian ticks which were likely to include those found in Jamaica 

 by Dr. Strachan. The question of remedy for this plague was 

 discussed by Dr. John Lowe, and Messrs. T. Christy, C. 

 Breeze, and T. J. Briant. 



Cambridge. 



Philosophical Society, November 23. — The following 

 communications were made : — The self-induction of two parallel 

 conductor.s, by Mr. H. M. Macdonaid. The well-known ex- 

 pression for the self-induction of two parallel wires (Maxwell, 

 § 685) holds only for the case when neither of them is magnetic. 

 For the case when both wires are magnetic, the value of the co- 

 efficient is found, in this paper, in the form of an infinite series. 

 This series can be expressed in finite terms when only one of the 

 wires is magnetic, and then gives 



L = Mm + Mo) + 2M0 log ^, -f 2M„^» log ^,, 



where /Uq is the permeability of the surrounding media (viz. 

 usually unity), a the radius of the magnetic wire of permeability 

 ju, a' the radius of the other wire, .and b the distance between 

 their lines of centres. The effect of the magnetic quality is ex- 

 hibited by means of numerical tables.— The effect of flaws on 

 the strength of materials, by Mr. J. Larmor. The effect of an 

 air-bubble of spherical or cylindrical form in increasing the 

 strains in its neighbourhood was examined ; and it was suggested 

 that the results might be of practical service in drawing general 

 conclusions as to the influence of local relaxations of stiffness of 

 other kinds. In particular, a cavity of the form of a narrow 

 circular cylinder, lying parallel to the axis of a shaft under 

 torsion, will double the shear at a certain point of its circum- 

 ference ; and the effect of a spherical cavity will not usually be 

 very different. It is assumed in the analysis that the distance of 

 the cavity from the surface of the shaft is considerable compared 

 with its diameter, so that the influence of that boundary may be 

 left out of account in an approximate solution. — The contacts of 

 certain systems of circles, by Mr. W. McF. Orr.— On liquid 

 jets, by Mr. H. J. Sharpe. The problem is treated by the 

 method of Fourier series. 



Dublin. 



Royal Society, November 18.— Prof. A. C. Haddon, 

 President of the Scientific Section, in the chair.— An analysis 

 of the spectrum of sodium, by Dr. G. Johnstone Stoney, 

 F.R.S. The position of the lines which present themselves in 



