240 



NA TURE 



[April 21, 1910 



which the flower appears. Flower and fruit are then fed 

 by the sap of the knob until fully developed, when nothing 

 is left of the sheltering knob except its skin. Another 

 species of Mesembrianthemum takes the same care of its 

 flower and fruit, nursing them within its own body ; but 

 it is even more cautious than its big brother, for it buries 

 itself entirely in the ground and shows only the apex of 

 its few leaves. As the ends of the leaves are flat, flush 

 with the ground, and coloured exactly like the rusty 

 gravel, it is practically impossible to detect them when 

 they are not in flower. Euphorbia elastica is the species 

 from which some sort of rubber has been manufactured in 

 Little Namaqualand, and, although the quality was not 

 good, it is not impossible that, with the present boom in 

 rubber, even those barren deserts may see a flourishing 

 industry. — R. A. Lehfeldt : Variation of gravity. There 

 have been differences of opinion as to the way in which 

 the value of gravity is affected by height above sea-level, 

 and special interest attaches to measurements on a really 

 larger tableland. The result of observations taken at 

 Johannesburg and Vereeniging is that the variation per 

 metre is 0-000236, considerably less than that given 

 by Helmert. — W. T. Saxton : The ovule of the 

 Bruniaceae. The main point brought out in this paper 

 IS that the ovule in the Bruniaceze is pendulous and 

 anatropous, with a dorsal raphe. There is a simple 

 massive integument with a long slender micropyle. — R. 

 Brown : Chrysocliloris natnaquensis, Brown. Chryso- 

 chloris natnaquensis was named from skulls found at 

 Garies in the disgorged pellets of owls. A description is 

 now given of the skin. A remarkable feature of the species 

 is that the third molar is about as frequently absent as 

 present. 



DIARY OF SOCIETIES. 



THURSDAY, April 21. 



Royal Society, at 4.30. — The Incidence of Light upon a Transparent 

 Sphere of Dimensions comparable with the Wave-lengtH : Lord Rayleigh, 

 O.M., F.R.S. — On the Improbability of a Random Distribution of the 

 Stars in Space: Prof. Karl Pearson, F.R.S.— The Total lonisation pro- 

 duced in Diflferent Gases bv the Kathode Rays ejected by X-Rays : 

 Dr. R. D. Kleeman. — Tone Perception in Gaminarus pnlex : Prof. F. J. 

 Cole. 



Royal Institution, at 3. — The Himalayan Region : Dr. Tom G. 

 Longstaff. 



Concrete Institute, at 8.— The Effect of Sewage and Sewage Gases 

 on Portland Cement Concrete : S. H. Chambers. 



Institution of Electrical Engineers, at 8. — Hydro-electric Installa- 

 tions of Sweden : A. V. Clayton. 



Royal Society of Arts, at 4.30.— The Arts and Crafts of Tibet, and 

 the Eastern Himalayas : J. Claude White. 



Royal Geographical Society, at 4.30. — Dewponds : E. A. Martin. 



LiNNEAN Society, at 8.— The Seedling and Adult K'nsxo'my oi Wehvitichia 

 vtirabilis : Miss M. G. Sykes. — Anthomyidae anf den Seychellen gesam- 

 melt: Prof. P. Stein. — The Dermaptera of the Seychelles: Dr. Malcolm 

 Burr. — The Pteropoda and Heteropoda collected by the Percy Sladen 

 Trust Expedition in the Indian r^cean : Dr. J. J. Tesch. — Die Pilzmiicken 

 Fauna der Seychellen : Dr. G. Enderlein. 



Optical Society, at 8.— Historical Exhibit of Spectacles : E. C. Bull.— 

 Abrasives and Polishing Materials : Dr. W. Rosenhain. 



FRIDAY, April 22. 

 Royal Institution, at 9.— The Telegraphy of Photographs, Wireless 



and by Wire : T. Thorne Baker. 

 Physical Society, at 5.— Further Tests of Brittle Materials under Com- 

 bined Stress : W. A. Scoble. — The Magnetic Balance of Curie and 



Cheneveau : C. Cheneveau with A. C. Jolley. 

 Institution of Civil Engineers, at 8.— The History and Present 



Method of Quay-wall Construction at the Port of Rotterdam : H. C. A. 



Thieme. 



SATURDAY, April 23. 

 Royal Institution, at 3.— Bells, Carillons and Chimes : W. W. Starmer. 



MONDA Y, April 25. 

 Royal Geographical Society, at 8.30.— The Aldabra and Neighbouring 



Islands in the South-west Indian Ocean : J. C. F. Fryer. 

 Royal Society of Arts, at 8.— Modern Methods of Brick-making: 



Dr. A. B. Searle. 

 Institute of Actuaries, at 5.— Analysis and Apportionment of the 



Expenses of Management of a Life Office with a view to ascertaining 



the Office Premium Loadings : H.J. Rietschel. 



TUESDA Y, April 26. 



Royal Institution, at 3.— The Mechanism of the Human Voice : Prof. 

 F. W. Mott, F.R.S. 



Faraday Society, at 8.— Is Water an Electrolyte? Prof. P. Walden.— 

 On the Nature of Molecular Association in the Special Case of Water : 

 Prof. Ph. Guye. — Liquid Water a Ternary Mixture. Solution-volumes 

 in Aqueous Solutions : W. R. Bousfield and Dr. T. M. Lowry.— The 

 Specific Heat of Gaseous, Solid, and Fluid Water : Communications 

 from William Sutherland and Prof. W. Nernst. 



Royal Anthropological Institute, at 8.15.— Mythology and Sup' 

 stiiions of the Lengua Indians of the Paraguayan Chaco: Rev. H. 

 Morrey Jones. 



Institution of Civil Engineers, at 8. 



WEDNESDAY, April 27. 



Geological Society, at 8. 



koYAL Society of Arts, at 8.— Irish Linen and some Features of it 



Production : Sir William Crawford. 

 British Astronomical Association, at 5. 



THURSDAY, April 28. 



Royal Society, at ^.-^o.— Probable Papers: On the Rotatory Character 

 of some Terrestrial Magnetic Disturbances at Greenwich and on their 

 Diurnal Distribution : R. B. Sangster. — The Chromophil Tissues and the 

 Adrenal Medulla: Prof. Swale Vincent. — The Liberation of Helium froi" 

 Minerals by the Action of Heat : D. O. Wood. 



Royal Institution, at 3. — Blackfeet Indians in North America: Walt' 

 McClintock. 



Institution of Electrical Engineers, at 8. — Earthed »^rjwj Insulated 

 Neutrals in Colliery Installations: W. W. Wood. 



Mathematical Society, at 5.30. — The Accuracy of Interpolation by 

 Finite Differences : Dr. W. F. Sheppard. — Note on Maclaurin's Test for 

 the Convergence of Series : G. H. Hardy. 



FRIDAY, April 29. 



Royal Institution, at 9. — Matavanu : a New Volcano in Savaii (Germ::', 

 Samoa) : Dr. Tempest Anderson. 



SA TURD A Y, April 30. 



Royal Institution, at 3.— The World of Plants before the Appearance 

 of Flowers : Dr. D. H. Scott, F.R.S. 



NO. 21 12, VOL. 83] 



The Correspondence of Gibers and Gauss. By 



J. L. E. D 211 



Colonial Fruit-growing 212 



Steam Tables. By H. E. Wimperis ....... 212 



Snake Venoms 213 



The Evolution of Man's Structure. By G. E. S. . 214 



Maps of the Thames Basin 215 



Early Views on Insect Life 215 



Our Book Shelf:— 



Becker and Van Orstrand : " Smithsonian Mathe- 

 matical Tables. Hyperbolic Functions " ; Lohse : 



"Tafeln ftir numerisches Rechnen mit Maschinen " 216 



Kohlrausch : " Lehrbuch der praktischen Physik " 216 

 " The Schoolmaster's Year-book and Directory," 



1910 217 



Bevan : " Egypt and the Egyptians " 217 



Letters to the Editor : — 



The Term " Radian " in Trigonometry. — ^James 



Thomson 217 



The Yellow Colour in the Stoat's Skin.— Dr. Henry 



O. Forbes 217 



Transit of Halley's Comet across Venus and the Earth 



in May. {Illustrated.) — Prof. Kr. Birkeland . . 217 

 Neutral Doublets at Atmospheric Pressure. — A. E, 



Garrett and J. J. Lonsdale 218 



The Etiology of Leprosy. — Sir Jonathan Hutchin- 

 son, F.R.S. ; The Writer of the Article ... 219 



Auroral Display.— R. M. Deeley 219 



The Free Atmosphere. {Illustrated.) By E, Gold . 220 

 The Hispar Glacier. {Illustrated.) By Prof. T. G. 



Bonney, F.R.S 222 



Halley's Comet. {Illustrated.) 223 



Roman Britain. {Illustrated.) 225 



Administration and Disease 226 



Notes 22 



Our Astronomical Column : 



Observations of Comets 2 



Objeclive-prism Determinations of Radial Velocities . 23 



Encke's Comet, 1895-1908 2 



The Spectra of the Major Planets 2 



The Intrinsic Brilliancy of the Sun 23: 



The Carnegie Institution of Washington .... 

 Recent Work of Geological Surveys. Ill, By 



G. A. J. C 231 



Papers on American Invertebrates 234 



Education in England and Abroad. By Otto Siep- 



mann 234" 



University and Educational Intelligence 237 



Societies and Academies 237 



Diary of Societies 24c 



