March 2, 19 16] 



NATURE 



27 



he chank itself. The shell-trumpet enters into cere- 

 nonies in Malabar, Siam, etc. ; and signal-horn shells 

 ire used in Japan. In certain of the Pacific Isles their 

 ises are many. In the Ne\y World the shell-trumpet 

 was known in pre-Columbian times, and entered into 

 Jie religious ceremonial of the Aztecs. Ancient 

 Mexican manuscripts provide evidence of its use in 

 ;emple worship in precisely the same way as in India. 

 Fhe shell-trumpet was also employed by the Incas 

 and other ancient peoples, and survives to-day in 

 several places. 



Dublin. 

 Royal Irish Academy, February 14.— Rev. J. P. 

 Mahaffy, president, in the chair. — J. G. Leathern: 

 Periodic conformal curve-factors and corner-factors. 

 rhe paper deals with the repeated conformal repre- 

 sentation of the doubly connected region which is 

 twunded internally by a closed curve or polygon and 

 is externally unbounded, upon successive semi-infinite 

 strips of a half-plane. Smooth curves are dealt with 

 by means of periodic conformal curve-factors ; and the 

 properties of such curve-factors and some comprehen- 

 sive formulae for them are discussed. Periodic comer- 

 factors are defined, and it is shown how they give 

 ^the required transformation in the case in which the 

 (internal boundary is polygonal. The periodic curve- 

 Ifactor is exhibited as the limit of a product of periodic 

 icorner- factors, and special types are deduced. The 

 results are interpretable in terms of two-dimensional 

 fields of liquid or electric flow, or electric induction. 

 : Fields with logarithmic singularities (sources, vortices, 

 electrodes, etc.) are then discussed, and it is shown 

 how, by a double transformation, such fields can be 

 specified for any region the conformal representation 

 of which has been formulated. Thus the field due to 

 a line-charge in presence of a charged conductor 

 in the_ form of an elliptic cylinder or a polygonal 

 prism is readily determined, and the method is equally 

 applicable to many other problems of similar type. — 

 G. H. Carpenter : The Apter}gota of the Seychelles. 

 The collection described was made by mernbers of 

 the Percy Sladen Trust Expedition, and comprises 

 thirteen species of Thysanura and eighteen of Collem- 

 bola. As only three Apterygota were hitherto re- 

 corded from the Seychelles, most of the species now- 

 enumerated are regarded as new, and three remark- 

 able Machilids are referred to a new genus. Struc- 

 tural details of the jaws of Isolepisma, Lepidospwra, 

 Lepidocampa, Heteromuricus, and Cremastocephalus 

 are given, together with an account of the genital 

 appendages in Lepidospora and Lepidocampa. The 

 presence of the latter genus in the Seychelles is of 

 considerable geographical interest; together with 

 some of the Collembolan genera it indicates Malayan 

 and Indian aflfinities for the fauna of the granitic 

 islands of the Seychelles proper, while the species 

 from the coral islands of the Farquhar and Aldabra 

 groups have on the whole Malagasv and African 

 relationships. 



Paris. 

 Academy of Sciences, Februarv 14.— M. Camille Jor- 

 dan in the chair. — G. Bigourdan : A work of F. Viet6, 

 supposed to be lost, "I'Harmonicon cceleste."— B. 

 Baillaud : Remarks concerning the determination of 

 the difference of longitude between the Observatories 

 of Paris and Washington. An account of the work 

 of the French-American Committee commencing 

 October, 1913, in which wireless signals between 

 Arlmgton and the Eiffel Tower were utilised. The 

 final result adopted is 5h. 17m. 36-67S.— Henry Le 

 Chatelier : The law of solubility. A replv to M. Col- 

 son. — T. H. Gronwall : Deformation in' conformable 

 representation.— CEchsner de Coninck and M. Gerard : 

 The atomic weight of bismuth. Bv the reduction of 



bismuth chloride in hydrogen the value 20850 was 

 obtained for the atomic weight of bismuth. — L, 

 Fernandez Navarro : The discovery of a basalt outcrop 

 in the Sierra de Guadarrama (Spain). This is the 

 only known volcanic outcrop in the centre of the 

 massif, — M. Deprat : The stratigraphic series in North 

 Tonkin. — Ph. Ulangeaud : The volcanic Pliocene of 

 the Saut de la Pucelle (Puy-de-D6me). — V. Vincent : 

 The circulation of manganese in natural waters. 

 Manganese is probably present in natural waters as 

 the bicarbonate. The oxides of manganese, in pre- 

 sence of carbon dioxide, do not dissolve to the same 

 extent as the carbonate. — G. Bourguignon : The stimu- 

 lation of ner\'es by discharges from condensers. — E. 

 Coiardeau and J. Richard : A stereoscopic arrangement 

 for the examination of radiographic proofs, either with 

 normal or pseudoscopic relief. — Ch. J. Gravier : The 

 madrepores collected by S.A.S. the Prince of Monaco 

 in the great depths of the North Atlantic. — A. 

 Vayssiere : A Notochiton and some Gasteropods from 

 the second exf>edition of Dr. Charcot. — J. Bounhiol 

 and L. Pron : A case of complete hermaphroditism in 

 Chrysophrys aurata. 



BOOKS RECEIVED. 



The Mathematical Theory of Probabilities and its 

 Application to Frequency Curves and Statistical 

 Methods. By A. Fisher. Translated and edited with 

 the assistance of W. Bonynge. Vol i.. Mathematical 

 Probabilities and Homograde Statistics. Pp. xx + 171. 

 (New York : The Macmillan Company ; London : 

 Macmillan and Co., Ltd.) 8s. 6d. net. 



Macmillan 's Greographical Exercise Books. iv., 

 The Americas. With Questions by B. C. Wallis. 

 Pp. 48. (London : Macmillan and Co., Ltd.) 6d. 



Thomas Alva Edison. By F. Rolt-Wheeler. Pp. 

 ix + 2oi. (New York: The Macmillan Company; 

 London : Macmillan and Co., Ltd.) 2s. net. 



Board of Agriculture and Fisheries. Fishery Inves- 

 tigations. Series ii.. Sea Fisheries. Vol. iii.. No. 2. 

 Report on Sexual Differentiation in the Biology and 

 Distribution of Plaice in the North Sea. Bv A. E. 

 Hefford. Pp. 73. (London: H.M.S.O.; Wyman and 

 Sons, Ltd.) 4s. 



National Health Insurance. Medical Research 

 Committee. Report of the Special Advisory Com- 

 mittee upon Bacteriological Studies of Cerebro-spinal 

 Fever during the Epidemic of 1915. Pp. 64. (Lon- 

 don : H.M.S.O. ; Wyman and Sons, Ltd.) 6d. 



Napier Tercentenary Memorial Volume. Edited by 

 Dr. C. G. Knott. Pp. xi + 441. (London : Published 

 for the Royal Society of Edinburgh by Longmans and 

 Co.) 2 IS. net. 



Wireless Transmission of Photogrraphs. By M. J^ 

 Martin. Pp. xi+117. (London : Wireless Press, Ltd.) 

 2S. 6d. net. 



Harvev's Views on the Use of the Circulation of the 

 Blood. By Prof, J. G. Curtis. Pp. xi+194. (New 

 York : Columbia University Press ; London : Oxford 

 University Press.) 6s. 6d. net. 



The Athenaeum Subject Index to Periodicals, 1915. 

 Science and Technology, with Special Reference to 

 the War in its Technological Aspects. Pp. 79. (Lon- 

 don : Athenaeum Office.) 2s. 6d. net. 



Woburn Experimental Fruit Farm. Fifteenth Re- 

 port of the Woburn Experimental Fruit Farm. Pp. 83. 

 (London : Amalgamated Press, Ltd.) 2s. :\d. 



British Fungi and How to Identifv Them. Bv 

 J. H. Crabtree. Pp. 62. (London : C. H. Kelly.) 

 IS. net. 



Instincts of the Herd in Peace and War. Bv W^. 

 Trotter. Pp. 213. (London: T. Fisher Unwin, Ltd.) 

 3s. 6d. net. 



NO. 2418, VOL. 97] 



