33^1 



NATURE 



[August 6, 1903 



the spirpm thread certainly undprgoes longitudinal, fissipij. 

 CbVihec^tfed with "this' there is- ^ stage when the thread is 

 ari'^riged in loops," the split sides q^ which are .approximated 

 togfether' in TJ-shaped figures.' ' Although at their first form- 

 ation the sides of these U-shapec} loops are far apart, and 

 still show the original longitudinal fission, they ultimately 

 becorrie approximated together, ' and* at the same time the 

 origirial fis'sioh, running throughout the length of the 

 loops, disappears from general view. Through this process 

 the approximated sides of the loops have hithertp been 

 generally mistaken for the thickened halves of the originally 

 split spirem thread, whereas in favourable cases it is seen 

 that this fission can still be traced running along both sides 

 of the loops. • 



/ The number of these loops arising during the synaptic 



/ rest corresponds , to the reduced number of the chromosomes, 

 and the further: process in the formation of these chromo- 

 somes' ig. sim|)|.y aithickening and shortening of the loops 



I already. fSrpied. 'When these become divided during the 

 next mi'tosis' tl;\ey break transversely at a point correspond- 

 ing fo.thie original bends of the loops, and as the halves 

 thus seVere'd 'separate, the original longitudinal fission can 

 be clearly traced running along their entire length. It is 

 thus this original fission of the spirem thread, which serves 

 to distribUteithe halves of the disunited, somatic chromo- 

 somes during the following homotype division, and the 

 hitherto enigmatical figures described by Flemming 

 Mev^s and others in the djaster of the heterotype find their 

 natural explanation; 



It would thus appear that the synapsis and the so-called 

 heterotype mitosis constitute a phase which has been 

 specially intercalated in the reproductive cycle. In it the 

 reduction ' in the number of the chromosomes is produced 

 by their adhesion in pairs, and the completion of the original 

 longittidinal fission of the spirem thi-ead is deferred until 

 the following hbmotype mitosis. 



The authors purposely refrain from discussing the general 

 bearing of t'hese observations, reserving this for a further 

 and more detailed comrnunication. 



Paris. 

 Academy of Sciences, July 27. — M. Mascart in the chair. 

 — The preparation and properties of a silicide of ruthenium, 

 by MM. Henri Moissan and Wilhem Manohbt. At the 

 melting point of ruthenium this metal combines with silicon 

 with ease, giving a silicide of the formula RuSi, of density 

 5-40, perfectly crystalline, . possessing great hardness, and 

 very stable In the presence of most reagents. — Arsenic in 

 sea-water, in rock-salt, kitchen salt, mineral waters, &c. 

 Its determination in some common reagents, by M, Armand 

 Gautier. — On dividing waves, by M. P. Duhem.— On cyclo- 

 hexane and its chlorine derivatives, by MM. Paul Sabatier 

 and Alph. Mailhe. The authors have shown that the 

 aromatic nucleus really persists in the hydrocarbon ; the 

 vapour of cyclohexane directed alone on to recently reduced 

 nickel maintained between 270° and 280° is regularly de- 

 composed, reforrri^j^ benzene and hydrogen, which at this 

 temperature rei^icts on the benzene, transforming it into 

 methane, 3CgHj2 = 2CgHg-|-6CH^. The presence of the aro- 

 matic nucleus is also proved by the reactions of the chloro- 

 derivatiyes. One monochlorocyclohexane, two dichloro-, 

 three ; trichloro-, and one tetrachloro-cyclohexane are de- 

 scribed. — Photograph of Borrelly's comet, 1903 c, by M. 

 Quervjsset. The photograph was taken at the Nanterre 

 Observatory on July 24-25, with an exposure of one hour. 

 The photograph shows that the coma measures 16' in 

 diameter, that is, a little more than half the apparent 

 diameter of the moon. Several tails can be distinguished, 

 the most luminous and longest of which is at least 7° 50' 

 in length. — On the conditions of synchronisation, by M. 

 Andrade. — On the measurement of the dichroism of 

 crystals, by M. Georges Meslin. — On the electrical 

 dichroism of liquids containing crystalline particles in 

 suspension, by M. J. Chaudier. With the advice of M, 

 Meslin, who has examined the modifications produced in 

 ordinary light by its passage through a liquid containing 

 crystalline ; particles and placed first in a magnetic field 

 and secondly in an electric field, the author has continued 

 the experiments with other mixtures in an electric field. A 

 certain number of the mixtures presented a decided 

 dichroism, which took a certain time to appear and dis- 



NO. 1762, VOL. 68] 



appear after the discontinuance of the field. The liquids ' 

 which entered into the composition of the active mixtures, 

 usually contained no oxygen. No direct relation seems to ■ 

 exist between the chemical properties of the solid and the 

 electrical dichroism it is able to cause when associated with 

 a suitable liquid. — On the separation of gaseous mixtures 

 by centrifugal force, by MM. G. Claude and E. Demoussy. 

 —On the laws and the equations of chemical equilibrium, 

 by M. Aries. — On a combination of two bodies which unite 

 as a result of an elevation of temperature then separate 

 below —79°, by M. D. Gernez. — Separation and simul- 

 taneous determination of baryta, strontia, and lime, by 

 M. Lucien Robin, — On the condensation of ethers with 

 alcohols, by M. Ch. Moureu. — On the composition of allyl 

 cyanurate, by M. R. Lespieau. — Contribution to the study 

 of the quinones-diketones, by M. CEchsner de Coninck. — 

 Albuminoid substances in Indian corn, by MM. Donard and 

 Labb^. — The use of a calorimetric bomb to demonstrate 

 the presence of arsenic in the organism, by M. Gabriel 

 Bertrand. With camphor or pure sugar no trace of arsenic 

 was obtained, but a few grams of tortoise-shell, of sponge, 

 of the white or yolk of an ^%^, gave clear indications of 

 arsenic. — Influence of temperature on the production of 

 sulphuretted hydrogen by albuminoid substances, extracts 

 of animal organs and extracts of yeast, in the presence of 

 sulphur, by MM. J. E. Abelous and H. Ribaut. — Re- 

 searches on the natural immunity of vipers and snakes, by 

 M. C. Phisalix. — On the spermatogenesis of decapod 

 crustaceans, by M. Alphonse Labbe. — :Artificial production 

 of gigantic larvae in an Echinoid, byi M. F. A. Janssens. 

 — Inscription of the variable state of the tension of the wire 

 of the ergograph : equation of the movement and expression 

 for the work, by MM. A. imbeirt and J. Gagrni'fere. — On 

 the production of gum in tissues, by M. G. Delacroix. — On 

 the trenchings of the plain of Sevran, by M. Gustaye F. 

 Dollfus. — On a new physical method of research ^'sd of 

 the determination of the watering of wines, by M, Georges 

 Maneuvrler. '^. 



CONTENTS. PAGE 



The Mineral W^ealth of Africa 313 



Rowland's Work. By R. T. G 316 



A Vine Disease 317 



Our Book Shelf:— 



Dutley : " Kinematics of Machines " 318 



Meyer : " Determination of Radicles in Carbon 



Compounds" — F. M. P 319 



Weed and Grossman: "A Laboratory Guide for 



Beginnerii in Zoology" 319 



Coolidge : "A Manual of Drawing " 319 



Pfurtscheller : " Zoologische Wandtafeln " 319 



Letters to the Editor : — 



Radium and Cancer.— Dr. Alexander Graham Bell; 



Dr. Z. T. Sowers 320 



The American Tariff and the St. Louis Exhibition. — 



Prof. C. V. Boys, F.R.S 320 



The Eucalypts. — D. E. Hutchins ; E. Hutchins . 320 

 A Simple Form of Tide Vi^6\c\.ox.—{lUttstrated.) 



R. W. Chapman 322 



Sympathetic Song in Birds. — Edgar R. Waite . . 322 

 Thirty Years of University Education in France. 



By Cloudesley Brereton 323 . 



The Resuscitation of the Apparently Drowned . . 326 



Notes 326 



Our Astronomical Column :— 



The Spectrum of o Ceti 330 



Photographic Efficiency of a Short Focus Reflector , 330 



The Godlee Observatory 330 



The Marine Biological Association 331 



The Parsons Steam Turbine 331 



Anthropological Notes. {Illustrated.) . 332 



A Buried Triassic Landscape. {Illustrated.) 



H. B. W . . 332 



University and Educational Intelligence 333 



Societies and Academies. {Illus-trated. ) 334 



