264 



NATURE 



[Jan. 16, 1890 



supra-axillaris, and the latter communicates them to the air. The 

 speaker was of opinion that the above was the explanation of the 

 "drumming" of this fish ; he was, at all events, unable to find 

 any other organ in it which could account for the noise. This 

 noise is not known to be emitted by other species of Balistes, 

 although it is known to occur in other groups. — Prof. Fritsch 

 spoke on the anatomy of Torpedo mannorata. In opposition to 

 the revolutionary views of many recent investigators, who deny 

 the nervous nature of the ganglion-cells, he laid great stress upon 

 the extremely close relationship which exists between the ganglia 

 and end-organs, and is so strikingly shown in Torpedo. A thick 

 nerve-fibre runs from each ganglion-cell to the electrical-organ, 

 divides into twelve to twenty-three fibrils before it reaches the 

 organ, and each of these fibrils is connected up with some one 

 special plate of the organ. Now, since each plate, which is of 

 hexagonal shape, owing to the close juxtaposition of the columns, 

 receives one nerve-fibre at each of its angles, it hence follows 

 that the number of the plates must be, on the average, three 

 times as great as the number of the ganglia. The fibres of one 

 ganglion supply eighteen plates, the latter (being hexagonal) 

 require six times eighteen fibres for tlieir supply, and since on an 

 average eighteen fibres run out from each ganglion, it requires 

 six ganglia to supply eighteen plates with nerves. The speaker 

 had counted the plates of an electrical-organ in Torpedo, and 

 obtained a number corresponding closely with an older enumera- 

 tion of Valentin's made on a Torpedo of the same size ; the 

 number of plates he found to be 179,625. He had further 

 counted the ganglion-cells which supply the plates with nerves 

 and found them to number 53,739 ; this corresponds closely with 

 the enumeration of Boll, who counted 53,760. The counting of 

 ganglion-cells is subject to much uncertainty, chiefly owing to 

 the fact that in sections of the central nervous system many cells 

 are cut through, and are thus liable to be counted twice : hence 

 the speaker had enumerated, most readily by means of photo- 

 graphs, the axis-cylinders of the nerves which supply the electric- 

 -organ ; he found them to number 58,318, corresponding to the 

 same number of ganglion-cells. The last number is nearly one- 

 third the number of plates in the electrical-organ, and corre- 

 sponds closely to the number which should be found if the older 

 view is the correct one, that the ganglion-cells are the centres for 

 ;the nervous end-organs. 



DIARY OF SOCIETIES. 

 London. 



THURSDA y, January 16. 

 ;RjVAL Society, at 4.30. — On the Chief Line in the Spectrum of the 



Nebulae : Prof. J. N. Lockyer, F.R.S. — Observations on the Excretion 



and Uses of Bile : A. W. Mayo Robson. — On the Theory of Free Stream 



Lines: J. H. Michell. 

 .LiNNEAN Society, at 8.— Life-History of a Remarkable Uredine on 



Jasminum grandiflora : A. Barclay. — Certain Protective Provisions in some 



Larval British Teleosteans : E. Prince. 

 Chemical Society, at 8.— On a New Method of estimating the Oxygen 



dissolved in Water : Dr. J. C. Thresh. 



;Z00L0GICAL SOCIKTV, at 4. 



FRIDAY, January 17. 



Society of Arts, at 8. 



Physical Society, at 5.— On a Carbon Deposit in a Blake Telephone 

 Transmitter : F. B. Hawes.— On Electric Splashes : Prof. S. P. Thompson. 

 —On Galvanometers : Prof. W. E. Ayrton, F.R.S. , T. Mather, and W. 

 E. Sumpner. 



SUNDAY, January 19. 



S iNDAT Lecture Society, at 4.— How I crossed Africa from the Indian 

 Ocean to the Atlantic (with Oxyhydrogen Lantern Illustrations) : Com- 

 mander V. L. Cameron, R. N. 



MONDAY, January 20. 

 Royal Geographical Society, at 8.30.— Mr. J. R. W. Pigott's Journey 

 to the Upper Tana in i«89 : E. G. Ravenstein.— The Mouths of the 

 Zambezi : Daniel J. Rankin. 

 ■Society of Arts, at 8.— The Electromagnet ; Dr. Silvanus P. Thompson. 

 Aristotelian Society, at 8.— The Universal : M. H. Dziewicki. 

 Victoria Institute, at 8.— Ancient Eastern Laws in Regard to Land: 

 Rev. J. Neil. 



TUESDAY, January 21. 



Society of Arts, at 5.— Tea, Coffee, and Cocoa Industries of Ceylon : 



John Loudoun Shand. 

 Institution op Civil Engineers, at 8.— Recent D^ck Extensions at 



Liverpool : George Fosbery Lyster. (Discussion.) 

 Royal Statistical Society, at 7.45. 

 iloYAL Institution, at 3.— The Post-Darwinian Period: Prof G. T 



Romanes, F.R.S. 

 iUnivkrsity College Biological Society, at 5 15. — Vegetarianism: W. 



North. 



WEDNESDAY, January 22. 



Society of Arts, at 8. — Vision-testing for Practical Purposes : R. Brudenell 



Carter. 

 Geological Society, at 8. — On the Crystalline Schists and their Relation 



to the Mesozoic Rocks in the Lepontine Alps : Prof T. G. Bonney, 



F.R.S.— The Variolitic Rocks of MontGenevre: Grenville A. J. Cole 



and J. W. Gregory. 



THURSDAY, January 23. 

 Royal Society, at 4.30. 



Institution of Electrical Engineers, at 8. 

 KOYAL Institution, at 3. — Sculpture in Relation to the Age: Edwin 



Roscoe MuUins. 



FRIDAY, January 24. 



Institution of Civil Engineers, at 7.30. — The Up-keep of Metalled 



Roads in Ceylon : Thos. H. Chapman. 

 Royal Institution, at 9. — The Scientific Work of Joule : Prof. Dewar 



F.R.S. 



SATURDAY, January 25. 



Royal Botanic Society, at 3.45. 



Royal Institution, at 3. — The Natural History of the Horse, and of 

 its Extinct and Existing Allies : Prof. Flower, F.R.S. 



BOOKS, PAMPHLETS, and SERIALS RECEIVED. 



A Search for Knowledge, and other Papers : A. N. Pearson (Melbourne). 

 — The Magic Lantern (Perkin). — The Fauna of British India, including 

 Ceylon and Burma ; Birds, vol. i. : E. W. Gates (Taylor and Francis). — A 

 Text-book of Animal Physiology : Dr. W. Mills CAppleton). — Our Earth 

 and its Story, vol. iii. : edited by Dr. R. Brown (Cassell). — Geological and 

 Natural History Survey of Canada ; Annual Report, vol. iii., Parts i and 2, 

 Maps, &c. , to accompany ditto (Montreal). — Stanley's Explorations in Africa ; 

 a new Map (Philip). — The Scenery of the Heavens : J. E. Gore (Roper and 

 Drowley). — Graphical Statics : L. Cremona ; translated by T. H. Beare 

 (Oxford, Clarendon Press). — Annuaire de I'Acadtfmie Royale de Belgique, 

 1890 (Bruxelles). 



CONTENTS. PAGE 



The New Muzzling Regulations 241 



Polytechnics for London 242 



Assaying. By Thomas Gibb 245 



Brewing Microscopy 246 



Our Book Shelf:— 



Fisher : " Flower-Land : an Introduction to Botany." 



— D. H. S 247 



Carbutt : " Five Months' Fine Weather in Canada, 



Western U.S., and Mexico" 247 



Letters to the Editor : — 



The Duke of Argyll and the Neo-Darwinians. — W. T, 



Thiselton-Dyer, C.M.G., F.R.S. \ 247 



The Microseismic Vibration of the Earth's Crust. — 



Prof. G. H. Darwin, F.R.S 248 



Meteor. — Rev. T. W. Morton 249 



Magnetism. I. {Illustrated.) By Dr. J. Hopkinson, 



F.R.S 249 



Lorenzo Respighi. By W. T. Lynn 254 



Notes 254 



Our Astronomical Column : — 



Objects for the Spectroscope. — A. Fowler 256 



The Temperature of the Moon 257 



On the Orbit of Struve 228 257 



Orbit of Swift's Comet (V. 1880) 257 



On the Variability of R Vulpeculas 257 



On the Rotation of Mercury 257 



On Certain Approximate Formulae for Calculating 

 the Trajectories of Shot. By Prof. J. C. Adams, 



F.R.S 258 



Societies and Academies 262 



Diary of Societies • . 264 



Books, Pamphlets, and Serials Received ..... 264 



