140 



NATURE 



[October 17, 19 18 



Tillyard, reveals the presence of the original archaic 



i; base ol the winy, where il fuses with 

 iA. The veins hitherto railed I'u, and Cu respec- 

 tively an shown to be, in reality, Cu,„ .in<l < u,,,. 

 \- a result, the position of the tribi Creagrini within 

 LI3 Dendroleontinae has to bi re\ ised, the 

 ncluded in it being shown to be much more 

 highh specialised than has hitherto been thought 

 possible. The phylogenetic stages b\ which the condi- 

 tion of ("n in the fore-wing of Myrmeleontidae has 

 been reached arc shown to be siiii existenl in some 

 ancient types of Hemerobiidae. (2) I In affinities oi 

 two interesting fossil ins. .is from the Upper Car- 

 boniferous ol Commentry, Ft ti 1 rhi paper dis- 

 1 lisscs the afllnitics "I I/. <a gfna! formis, 



Bolton, ami Sycopteron symmetrica, Bolton, described 

 from the types in the "Mark Stirrup" collection, 



Manchester Museum. The former is assigned h\ 

 Bolton to the Perlaria. with possible relationship to 

 the Sialtdae. These affinities are disproved, and the 

 Suggestion is made thai, the insect is, in reality, an 



ancient representative of the Embioptera. A detailed 

 comparison is made with the recenl genus Qligotoma. 

 The Sycopteron i~ assigned by Bolton to the 

 Mecoptera This is shown to be extremely doubtful, 

 and a much .loser resemblance is proved between the 

 fossil and the Psocopterous genus Amphientomum 

 ■ tie and recent), 



April 24. Prof. II. (i. Chapman, president, in the 

 chair.— Dr. II. I.. Kesteven : The origin of yolk in the 

 ova of an . ndoparaskic Copepod.- Or. R. Greig 

 Smith; Contributions to a knowledge of soil fertility. 

 Xo. 16 : The search for toxin producers. It has been 

 show u that certain soil bacteria, moulds, and amoebze, 

 all reasonably supposed to he capable of furnishing 

 substances ol a toxic nature, were grown in various 

 media and under varying conditions, and in nil cases 

 the sie n ^ of toxicity which became manifest could be 

 attributed to an alteration in the reaction of the media. 

 The test organism. Bacterium prodigiosus, grows best 

 in a neutral medium, and an indicator is required 

 which will indicate strict neutrality. The methyl- 

 orange numhe.s are too high, and the phenolphthalein 

 too low. Small divergences from the neutral point 

 strongly affect the FWwth. The humus of leaf-mould 

 contains two types of humic acid ; one absorbs alkali 

 from alkaline carbonates, and the other from alkaline 

 carbonates and hydrates. These wen present to the 

 extent of one part of the former to three of the latter. 

 ing the humus increases the amount of .aid, and 

 as. is largely soluble in water. The effect of 

 n is auite of a different order from the evidence 

 of to: iction obtained in formei researches. -J. J. 

 Fletcher and C. T. Musson : Certain shoot-b 

 tumours of Eucalypts and Angophoras. and their 

 niod : '11c. on the -rowth-hahil of the plants. 



BOOKS RECEIVED. 

 A Mem,, ,n British Resources of Refractor? Sands 

 fot Furnai Purposes. Parti. Bj Prof. 



P- G. II. Boswcll, with Chemical Analyses by Dr. 

 H. !•'. Harwoocl and A. \. Eldridge. Pp. xii + 2464 

 plates xi. (London lot and Francis.) 8f.6d.net. 



The Mod. in he triangle. By W. Gal- 



latly. Second edition. Pp. \ii [ 2 6. (London: F. 

 Hodgson 1 2S. '.'<!. net. 



\ ( '1 iiicd Revision of tb< ut alyptus. By 



I. II. Maiden. Vol. iv., part 5. S) ie\ 1'h. i Govern- 

 oi the Slate of New South Wall 

 lies in Clocks and Time-keeping No. 2. Tables 

 NO. 2555, -VOL. I02] 



..I ih. 1 ti.ular Equation. Bv Prof. R. A. Sampson*. 

 (Edinburgh: R. Grant and Son.) 2s. lod. 



A Monograph of the British Lichens: \ Descrip- 

 tive Catalogue of the Species in th< Department oi 

 British Museum. By A. Lorrain smith. 



Second edition. Pp. Xxiv + 520 + 71 plates, (London: 



British Museum (Natural History).) 3o». 



DIARY OF SOCIETIES. 



THURSDAY, October 17. ' 



Institution el Ga>- Enginffrs, at 10. — l.t.-Col. Arthur Smithells and 

 I'rof. lohn W.Cobb: Preliminary Report of llie Gas Invest.. 

 mittec.-B. k. Parkinson': Life of Gas Meters Research Committee 

 Communications on "Unaccounted-for Gas." — J. G. Taplay : Corrosion 

 of Dry Gas Meters— Dr. J. W. Mellor : Report of Refractory Materials 

 Committee.— Wall, :i fernery and Dr. A. Scott : The Corrosive Action of 

 Flue-dust on Fire Itricks. 



FRIDAY, October 18. 

 Institi ii n 01 ( . Engineers, at 10. — Papers from list given above. 

 Institution of Mechanical Enginffrs, at 6. 



TUESDAY, October 22. 



Zoological SOCIETY, at 5.30.— Prof. H. M. Lefroy : Wheat Weevil in 



Australia. -Sir E. G. I.oder. Bart. : Notes on the Beavers al Leonardslee, 



1916-18. — G. A. Roulenger : The Madagascar Frogs of the Genus 



Mantidactylus, B 



CONTENTS. page 



The Salvage of Nineteenth-century Science . . . 121 



A Text-book of Plant Physiology. By V. H. B. . 121 



Fundamental Principles of Chemistry. By J. K. W. 122 



Optics in Euclid's Tims. By G. H. B 123 



Our Bookshelf 123 



Letters to the Editor: — 



The Perception of Sound. — Prof. W. M. Baylss, 



F.R.S 124 



Rainbow Brightness.— Chas. T. Whitmell .... 125 



An "Arbor' Day. — John Hopkinson 126 



Students' Microscopes on Loan. — Dr. Richard 



Wilson 126 



The Future of the Coal Trade. By Prof. H. Louis . 126 



Scientific and Industrial Research 128 



Notes 129 



Our Astronomical Column : — 



Large Meteors 132 



Observations of Long-period Variables 133 



Correction of Apparent Stellar Magnitudes 133 



Inter-Allied Conference on International Scient.fic 



Organisations 133 



The Johannesburg Meeting of the South African 



Association 134 



Report of the Suivey of India. By T. H. H. . . 135 

 Physics in Relation to National Life. By Sir 



Richard Glazebrook, C.B., F.R.S 135 



University and Educational Intelligence 139 



Societies and Academies 139 



Books Received 140 



Diary of Societies 140 



Editorial and Publishing Offices : 



MACMILLAN AND CO., Ltd.. 



ST. MARTIN'S STREET, LONDON, W.C.2. 



ments iind business letters to be addressed to the 

 Publishers. 



Editorial Communications to the Editor. 

 Telegraphic Address: Phusis, London. 

 Telephone X umber Gerrarp 8830. 



