Philosophical Transactions 



1909- I9I0. 



SERIES A. CONTAINING PAPERS OF A MATHEMATICAL OR PHYSICAL 

 CHARACTER. 



Vol. 208 (1908). Pp.530. Wiih 33 Plates. Price £1 18s. 6d. 

 Vol. 209(1909). Pp.480. With 13 Plates. Price £ I 13s. Od. 



SERIES B. CONTAINING PAPER5 OF A BIOLOGICAL CHARACTER. 



Vol. 199(1908). Pp.428. With 37 Plates. Price £11 6s. Od. 

 Vol. 200 (1909). Pp.524. With 37 Plates. Price £2 5s. 6d. 



SOLD BY HARRISON & SONS. 45, ST. MARTIN S LANE, W.C. 



RECENT PAPERS IN THE PHILOSOPHICAL TRANSACTIONS. 



Sold separately by Dulau & Co., Ltd., 37, Soho Square, London, W. 



A. 455. ON THE ELECTRICITY OF RAIN AND ITS ORIGIN IN THUNDER- 

 STORMS. By GEORGE C. SIMPSON, D.Sc. Pp. 35. Price 2s. 



A. 456. FUNCTIONS OF POSITIVE AND NEGATIVE TYPE, AND THEIR CON- 

 NECTION WITH THE THEORY OF INTEGRAL EQUATIONS. By 

 J. MERCER, B.A.. Trinity College, Cambridge. Pp. 32. Price 2s. 



A. 457. THE SPECTRUM OF MAGNESIUM HYDRIDE. By A. FOWLER, A.R.C.S., 

 F.R.A.S., Assistant Professor of Physics, Imperial College of Science and Technology, 

 South Kensington. Pp. 32 ; 2 Plates. Price 2s. 6d. 



A. 458. TITLE, CONTENTS, INDEX, &c.. Vol. 209. Pp. 10. Price 6d. 



A. 459. A WAVE-LENGTH COMPARATOR FOR STANDARDS OF LENGTH : AN 

 INSTRUMENT FOR FINE MEASUREMENT IN WAVE-LENGTHS OF 

 LIGHT. WITH AN APPENDIX ON THE USE OF WAVE-LENGTH 

 RULINGS AS DEFINING LINES ON STANDARDS OF LENGTH. By 

 A. E. H. TUTTON, M.A., D.Sc, F.R.S. Pp. 34. Price 2s. 



A. 460. THE ELASTIC LIMITS OF IRON AND STEEL UNDER CYCLICAL 

 VARIATIONS OF STRESS. By LEONARD BAIRSTOW, A.R.C.Sc, Wh.Sch. 

 Pp.21. Pricels. 6d. 



A. 461. A CRITICAL STUDY OF SPECTRAL SERIES. PART I.— THE ALKALIES 

 H AND He. By W. M. HICKS, Sc.D., F.R.S. Pp. 55. Price 2s. 6d. 



A. 462. THE DIFFRACTION OF ELECTRIC WAVES ROUND A PERFECTLY 

 REFLECTING OBSTACLE. By H. M. MACDONALD, F.R.S., Professor of 

 Mathematics in the University of Aberdeen. Pp. 32. Price 2s. 



B. 268. THE ACTION OF THE VENOM OF SEPEDON H./tMACHATES OF SOUTH 



AFRICA. By Sir THOMAS R. ERASER, M.D., LL.D.. Sc.D., F.R.S., Professor 



of Materia Medica, University of Edinburgh ; and JAMES A. GUNN, M.A., B.Sc, M.D., 



Assistant in the Materia Medica Department, University of Edinburgh. Pp. 29. Price Is. 6d. 

 B. 269. THE PROPORTION OF THE SEXES PRODUCED BY WHITES AND 



COLOURED PEOPLES IN CUBA. By WALTER HEAPE, M.A., F.R.S., 



Trinity College, Cambridge. Pp. 60. Price 3s. 

 B. 270. FURTHER OBSERVATIONS ON WELWITSCHIA. By H. H. W. PEARSON, 



Sc.D.. F.L.S. Pp. 72 ; 9 Plates. Price 6s. 

 B. 271. THE INTRACRANIAL VASCULAR SYSTEM OF SPHENODON. By 



ARTHUR DENDY, D.Sc, F.R.S., Sec. L.S., F.Z.S., Professor of Zoology in King's 



College (University of London). Pp. 24 ; 1 Plate. Price 2s. 

 B. 272. THE GIANT NERVE CELLS AND FIBRES OF HALLA PARTHENOPEIA. 



By J. H. ASHWORTH, D.Sc, Lecturer in Invertebrate Zoology in the University of 



Edinburgh. Pp. 95 : 6 Plates. Price 12s. 6d. 

 B. 273. TITLE, CONTENTS, INDEX, &c. Vol. 200. Pp. 10. Price 6d. 

 B. 274. STUDIES ON THE STRUCTURE AND AFFINITIES OF CRETACEOUS 



PLANTS. By MARIE C. STOPES, D.Sc, Ph.D., F.L.S., Lecturer in Fossil Botany 



in the University of Manchester, and K. FUJII, Ph.D., Assistant Professor of Botany in the 



Imperial University of Tokio. Pp. 90 ; 9 Plates. Price 6s. 6d. 



