September 20, 1900] 



NATURE 



501 



After an interval of about two years, Sir George King, late 

 superintendent of the Royal Botanic Garden, Calcutta, continues, 

 in ihc Journal of the Asiatic Society, Bengal, his materials for a 

 flora of the Malayan Peninsula. The present part consists of a 

 monograph of the Malayan species of Melastomaceoe, prepared 

 with the assistance of Dr. O. Stapf, of the Kew Herbarium. 



In an article on the fertilisation of Peronospora parasitica in 

 the Annals of Botany for June, Mr. Harold Wager points out 

 that there are at present known three distinct types of fertilisa- 

 tion in the Peronosporese. In the first, represented by Perono- 

 spora parasitica, the oosphere and oospore are uninucleate, and 

 fusion takes place between two nuclei only. In the second 

 type the oosphere is uninucleate and the oospore multinucleate, 

 and fusion is effected between two nuclei only. In the third 

 type the oosphere and oospore are both multinucleate, and 

 fusion takes place between a number of nuclei in pairs. 



In a paper recently read before the Linnean Society, on the 

 origin of the Basidiomycetes, Mr. G. Massee points out the 

 connection between the Hyphomycetes and the Protobasidio- 

 mycetes. The conidial forms of many Hyphomycetes are true 

 Protobasidiomycetes. There is no evidence that the Autobasi- 

 diomycetes are in any way descended from the Protobasidio- 

 mycetes ; while, on the other hand, there are indications that 

 the Autobasidiomycetes may probably have been derived by 

 gradual modifications of the spore-bearing organs or oasids of 

 conidial forms of certain ascigerous fungi. 



Prof. J. J. Thomson's inspiring work on " The Discharge 

 of Electricity through Gases" (Constable and Co.) has been 

 translated into French by Dr. L. Barbillion, and published by 

 MM. Gauthier-Villars under the title " Les Decharges 

 electriques dans les Gaz." Dr. Barbillion adds a few notes, 

 and Dr. C. E. Guillaume contributes a preface. The original 

 volume was reviewed in Nature of January 12, 1899 (vol. lix. 

 p. 241), and the translation will doubtless be received by French 

 physicists with the same appreciation as the work has commanded 

 in Great Britain. 



Several articles of real interest to students of science and 

 philosophy have appeared in recent numbers of The Open Court. 

 The August number contained an account of Galileo in which 

 his work is presented in new aspects, and the opposition to his 

 conclusions as to the movements of the earth and the character 

 of the visible universe is in some part explained. The current 

 number contains an instructive contribution on Greek religion 

 and mythology, by the editor. Dr. Paul Carus, and one on animism 

 in popular thought and in science, by Prof. E. Mach. Many 

 of the articles in the magazine are excellently illustrated. 



An atlas for druggists and students of pharmacy, by Prof. 

 Ludwig Koch, is in course of publication by the firm of 

 Gebriider Borntraeger, Leipzig, under the title of " Die 

 mikroskopische Analyse der Drogenpulver." The first volume 

 is to be devoted to barks and woods, and the second part of it, 

 containing six plates, has just appeared. 



The third and fourth parts of Dr. Chun's elaborate account of 

 the German Valdivia expedition have just been publiehed by 

 the firm of Gustav Fischer, Jena. The parts are illustrated with 

 numerous half-lone figures and some very fine plates, and the 

 work promises to be a very attractive narrative of an extensive 

 voyage. 



Thb additions to the Zoological Society's Gardens during the 

 past week include a Sooty Mangabey ( Cercocebus fuliginosus) 

 from West Africa, presented by Mr. B. Stewart ; a Squacco 

 Heron (Ardca ralloides), South European, presented by Mr. 

 A. F. Putz; a Black-headed Terrapin {Damonia reevesi uni- 

 <olor') from China, an Algerian Skink {Eumeces algeriensis) from 

 North-west Africa, a Common Chameleon {Chamaeleon vul- 

 NO. 16 I 2, VOL. 62] 



garis) from North Africa, presented by Mr. F. J. Bridgman ; 

 an European Pond Tortoise (Emys orbicularis), European, pre- 

 sented by Miss F. M. Weippert ; a Wall Lizard {Lcuerta 

 muralis), a Tessellated Snake (Tropidonotus tessellatus), Euro- 

 pean, presented by Mr. Walter Hunter ; two Badgers {Meles 

 taxus), British; two Indian Fruit Bats (Pteropus medius) from 

 India, three Black-spotted Teguexins ( Tupinanibis nigropunc- 

 tatus) from South America, two Antillean Boas {Boa diviniloqua) 

 from the West Indies, five Undulated Lizards (Sceloporus undu- 

 lalus) from South-east United States, deposited. 



OUR ASTRONOMICAL COLUMN 



Ephemeris for Observations of Eros :— 



R.A. 



Decl. 



Sept. 



+ 40 47-1 

 41 99 

 41 32*8 



41 557 



42 i8-6 



42 41-4 



43 4 -2 

 43 27-0 



43 497 



44 12-3 

 + 44 34 "8 



2 39 43 

 40 20 



40 55 



41 27 



41 56 



42 23 



42 46 



43 7 

 43 25 

 43 40 



2 43 SI 



Swift's Comet (1892 I.).— In the Annals of Harvard 

 Colles^e Observatory (vol. xxxii. Part ii. pp. 267-295), Prof. 

 W. Pickering describes the photographs obtained of this comet 

 at Arequipa during March and April 1892, illustrating his 

 remarks by reproductions from nine of the negatives. 



The plates were taken with four instruments — the 13-inch 

 Boyden telescope, 8inch and 2'5-inch doublets, and a 20-inch 

 reflector ; two photographs were also obtained with the 8-inch 

 refractor provided with an objective prism of 13° refracting 

 angle. The exposures varied from 5 to 133 minutes. 



While the comet was easily visible to the naked eye, it was 

 carefully examined with a double image prism, but no traces of 

 polarisation could be detected in either the head or tail. The 

 nucleus was yellowish-green in colour, giving out a triangular 

 jet towards the sun. 



The head was distinctly divisible into three parts — nucleus, 

 bright primary envelope and an outer fainter one. The tail 

 was composed of two sets of rays having distinctly different 

 origins. The brighter of these sets, forming what may be 

 called the ' ' inner " tail, took its origin from the rear side of 

 the inner envelope, and in some of the photographs this attains 

 the great length of over 20° of arc. The rays were absolutely 

 straight so far as could be determined from the photographs, 

 and were inclined to each other about 10". The outer tail 

 sprung from the external faint envelope, and, in contrast to the 

 other, was marked by conspicuous deep and wide rifts between 

 the rays composing it. 



Prof. Pickering thinks that certain periodic differences in 

 appearance are caused by a rotation of the comet about an axis 

 passing longitudinally through the tail. Comparisons of the 

 Arequipa photographs with others obtained by Dr. Wolf and 

 Prof. Barnard show that it is quite possible to detect changes 

 from one hour to another, and from a detailed examination of 

 the angular deviation of the rays it is probable that the rotation 

 period is about 94-97 hours. 



The photograph taken April 14 shows a strong deflection of 

 the inner tail, but the absence of other photographs near that 

 date render it impossible to trace the cause, and the pheno- 

 menon was not subsequently repeated. 



In general, it was impossible to identify any particular feature 

 on two successive days, but on April 6, 7, 8, a bright conden- 

 sation was noticed each day, and its distance from the nucleus 

 of the comet was found to increase day by day. These dis- 

 placements were carefully measured, converted into kilometres 

 by reference to the comet's elements, and an estimate made of 

 the amount of the repulsive force exerted upon the comet's 

 tail by the sun. This indicated the total repulsive force to be 

 about 39 '5 times the gravitational force. The spectrum photo- 

 graphs have been difficult to reduce, but the brightest region of 

 the spectrum appears as an intense and very narrow line about 

 A 3890. No indications of the hydrogen lines were seen. 



