March 31, 1892. An Improved Apparatus for ascertaining the Sensitiveness of Safetylamps when used for Gas-testing. By Frank Clowes, D.Sc. (Lond.), Professor of Chemistry, University College, Nottingham....... ...... On the Application of a Hydrogen Flame in an ordinary Safety-lamp Aberration Problems: a Discussion concerning the Connexion between The Abductor and Adductor Fibres of the Recurrent Laryngeal Nerve. 102 Interference with Icterus in Occluded Ductus Choledochus. By 116 116 No. 309. The Nature of the Shoulder Girdle and Clavicular Arch in Sauropterygia. By H. G. Seeley, F.R.S., Professor of Geography, King's College, London. Report of the Kew Committee................. No. 310. First Report to the Water Research Committee of the Royal Society, on the present State of our Knowledge concerning the Bacteriology of Water, with especial reference to the Vitality of Pathogenic Schizomycetes in Water. By Percy F. Frankland, Ph.D., B.Sc. (Lond.), F.R.S., Professor of Chemistry in University College, Dundee, and Marshall Ward, Sc.D., F.R.S., F.L.S., Professor of Botany in the Royal Indian Engineering College, Coopers Hill........... 119 152 183 No. 311. Report of the Committee on Colour-Vision. [Plate 2] 281 Evidence taken by the Committee 306 Letters received by the Committee bearing on the Enquiry.... 357 368 No. 312.—April 28, 1892. On a decisive Test-case disproving the Maxwell-Boltzmann Doctrine Page 397 399 On the Mathematical Theory of Electro-magnetism. By Alex. McAulay, M.A., Ormond College, Melbourne 400 Stellar Photometry. By W. J. Dibdin, F.I.C., F.C.S., &c..................... 404 408 List of Presents.............. 439 No. 313.-May 5, 1892. List of Candidates recommended for Election 443 Transmission of Sunlight through the Earth's Atmosphere. Part II. On the Simultaneity of Magnetic Variations at different places on occasions of Magnetic Disturbance, and on the relation between Magnetic and Earth Current Phenomena. By William Ellis, F.R.A.S., Superintendent of the Magnetical and Meteorological Department, Royal Observatory, Greenwich On the Liquation of Metals of the Platinum Group. By Edward 444 445 447 The Potential of an Anchor Ring. By F. W. Dyson, Fellow of Trinity College, Cambridge 448 On the Residues of Powers of Numbers for any Composite Modulus, On the Probable Effect of the Limitation of the Number of Ordinary Fellows elected into the Royal Society to Fifteen in each Year on the eventual total Number of Fellows. By Lieut.-General R. Strachey, R.E., F.R.S. 463 On the Shoulder Girdle in Ichthyosauria and Sauropterygia. By J. W. 471 On the Embryology of Angiopteris evecta, Hofm. By J. Bretland 471 Note on Excretion in Sponges. By George Bidder 474 List of Presents.............. 484 May 19, 1892. On Nova Auriga. By William Huggins, D.C.L., LL.D., F.R.S., and On the Changes produced by Magnetisation in the Length of Iron and other Wires carrying Currents. By Shelford Bidwell, M.A., LL.B., F.R.S. On the Measurement of the Magnetic Properties of Iron. By Thomas Page 486 495 ......... 503 On the Development of the Stigmata in Ascidians. By Walter Garstang, 505 Observations on the Post-Embryonic Development of Ciona intestinalis 513 520 PROCEEDINGS OF THE ROYAL SOCIETY. March 3, 1892. Mr. JOHN EVANS, D.C.L., LL.D., Treasurer, in the Chair. A List of the Presents received was laid on the table, and thanks ordered for them. In pursuance of the Statutes, the names of the Candidates for election into the Society were announced, as follows: Armstrong, Robert Young, Lieut.- | Gotch, Francis, M.R.C.S. Col. Beddard, Frank Evers, M.A. Ewart, Professor J. Cossar, M.D. M.A. Foster, Professor Clement Le Gadow, Hans, M.A. Giffen, Robert, LL.D. VOL. LI. Matthey, Edward, F.C.S. Notter, James Lane, Surgeon- Smith, Rev. Frederick John, M.A. Stevenson, Thomas, M.D. Oliver, John Ryder, Major-General Tuke, Daniel Hack, M.D. Ulrich, Professor George Henry Veley, Victor Hubert, M.A. Worthington, Professor Arthur Young, Professor Sydney, D.Sc. The Right Hon. Spencer Compton Cavendish, Duke of Devonshire, a Member of Her Majesty's Most Honourable Privy Council, whose certificate had been suspended as required by the Statutes, was balloted for and elected a Fellow of the Society. I. "Certain Correlated Variations in Crangon vulgaris." By W. F. R. WELDON, M.A., F.R.S., Fellow of St. John's College, Cambridge, Professor of Zoology in University College, London. Received February 11, 1892. The first successful attempt to find a constant relation between the variations in size exhibited by one organ of an animal body and those occurring in other organs was made some three years ago by Mr. Galton; and in a paper read before the Royal Society (Roy. Soc. Proc., vol. 45, p. 135) he determined this relation between several organs of the human body. In what follows an attempt is made to apply Mr. Galton's method to the measurement of the correlation between four organs of the common shrimp. Before the details of the measurement are discussed, a short summary of the method will be given. Galton's starting point was the fact that each organ of a given race of men varies about its mean size to an extent and with a frequency If two indicated by the probability equation (y = A T.C e-xα). variable organs are known to vary in this way, and if they are so |