iv Contents. 



No. PAGE 



XIII. — Forbesia cancellata, gen. et sp. nov. (Sphenopteris, sp., Baily.) 

 By T. Johnson, d.sc, f.l.s. (Plates XIII. and XIV.) (January 

 19, 1912.) ....... 177 



XIV. — The Inheritance of the Dun Coat-Colour in Horses. By James 



Wilson, m.a, b.sc. (January 19, 1912.) . . . 184 



XV. — On the Vacuum Tube Spectra of the Vapours of some Metals and 

 Metallic Chlorides. Part I. — Cadmium, Zinc, Thallium, 

 Mercury, Tin, Bismuth, Copper, Arsenic, Antimony, and 

 Aluminium. By James H. Pollock, d.sc. (Plates XV. and 

 XVI.) (February 21, 1912.) . . . . .202 



XVI.— Changes in the Osmotic Pressure of the Sap of the Developing 

 Leaves of Syringa vulgaris. By Heney H. Dixon, sc.d., f.k.s., 

 and W. R. G. Atkins, M.A. (February 21, 1912.) . -.219 



XVII. — Improvements in Equatorial Telescope Mountings. By Sir Howaed 



Geubb, f.k.s. (Plates XVII.-XIX.) (March 26, 1912.) . 223 



XVIII. — Variations in the Osmotic Pressure of the Sap oillex Aquifolium. 

 By Henky H. Dixon, so.d., f.r.s., and W. E. G. Atkins, m.a., 

 A.i.c. (April 9, 1912.) .. . . . .229 



XIX. — Variations in the Osmotic Pressure of the Sap of the Leaves of 

 Hedera Helix. By Henry H. Dixon, so.d., f.r.s., and W. E. G. 

 Atkins, m.a., a.i.c. (April 9, 1912.) . . . .239 



XX. — Heterangium hibernicum, sp. nov. : A Seed-bearing Heterangium 

 from County Cork. By T. Johnson, d.sc, f.l.s. (Plates XX. 

 and XXI.) (April 12, 1912.) . . . .217 



XXI. — On the Vacuum Tube Spectra of some Metals and Metallic 

 Chlorides. Part II. — Lead, Iron, Manganese, Nickel, Cobalt, 

 Chromium, Barium, Calcium, Strontium, Magnesium, 

 Potassium, Sodium, and Lithium. By James H. Pollok, d.sc. 

 (Plates XXIL and XXIII.) (May 7, 1912.) . . .258 



XXII. — The Ultimate Lines of the Vacuum-tube Spectra of Manganese, 

 Lead, Copper, and Lithium. By Genevieve V. Morrow, 

 A.R.o.so.i. (Plate XXIV.) (May 11, 1912.) . . 269 



XXIII. — Award of the Boyle Medal to Sir Howard Geubb, f.r.s., April 16, 



1912. (May 18, 1912.) . . . . .288 



XXIV. — Notes on Dischidia rafflesiana, Wall., and Dischidia nummularia, 

 Br. By A. F. G. Kerr, m.d. (Plates XXV.-XXXI.) 

 (September 30, 1912.) . . . . .293 



XXV. — Rechei'ches Experimentales surla Density des Liqaides en dessous 



de 0°. Par Jean Timmekmans. (October 18, 1912.) . . 810 



XXVI. • — Steady and Turbulent Motion in Gases. By John J. Dowling, m.a. 



(Plates XXXII. and XXXIII.) (November 16, 1912.) . 375 



