Febuuary 6, 190SJ 



NATURE 



325 



In ^ng,ineeting of January 31 there is a sympathetic 

 airount of the career of Dr. Coleman Sellers, the eminent 

 American engineer, who died on December 28, 1907, at h'.s 

 residence in Philadelphia in his eighty-first year. He was 

 best known in connection with machine tools, but he will 

 also be remembered for his scheme for utilising the water- 

 power of Niagara Falls, and by his inventions in photo- 

 graphy and microscopy. 



.\ CORRKSPONDENT asks if the use of wires stretched 

 horizontally at a height of 15 feet or 20 feet in concert 

 halls, churches, and other buildings where the acoustic 

 properties are of the first importance is not based upon 

 erroneous ideas. He expresses the opinion that though the 

 wires are supposed to remedy some fault in the acoustics, 

 thcv do not produce any useful effect. We are informed 

 th.it, theoretically, the wires absorb some of the energy 

 and radiate it again in all directions, thus diminishing the 

 amount of regular reflection, constituting echoes, from the 

 walls. But the fraction of the vibrations thus treated is 

 so small that it is difficult to believe the wires have any 

 re.il, beneficial effect. 



Mk. H. F. Witherbv, editor of Brilish Birds, informs 

 u^ that an inquiry is being made into the nature and 

 orit;in of the disease from which many wood-pigeons have 

 died this winter. The subject is of considerable interest ; 

 moreover, possibly the disease, which is very infectious 

 among wood-pigeons themselves, may also be contracted 

 bv other birds, and especially game birds. A systematic 

 inquirv into the disease has therefore been undertaken, and 

 schedules of questions have been posted to readers of 

 British Birds, the editor of which will be glad to send 

 schedules to anyone who may be in a position to give 

 information on the subject. All the observations will be 

 collated and studied by Dr. C. B. Ticehurst, of Guy's 

 Hospital, who will draw up a full report at a later date. 



The fourth International Congress of Mathematics will 

 be held in Rome on .April 6-1 1. The congress will be 

 divided into four sections. The first section will be con- 

 cerned with arithmetic, algebra, and analysis, and dis- 

 cussions will be inaugurated by Profs. .Arzela, Capelli, 

 Pascal, and Pincherle. The second section will deal with 

 geometry, and the work will be introduced by Profs. 

 Bianchi and Segre. The third section, covering inechanics, 

 mathematicaf physics, geodesy, and various applications of 

 mathematics, will be addressed by Profs. Levi-Civita, 

 Luiggi, Pizzetti, and Toja. The fourth section will take 

 up philosophical, historical, and didactical questions, and 

 addresses will be given by Profs. Enriques, Loria, and 

 Vailati. Numerous lectures have been arranged, and 

 among these may be mentioned that by Prof. Forsyth, 

 F.R.S., on the present condition of partial differential 

 equations of the second order, as regards formal integra- 

 tion. Other lectures will be delivered by Profs. Darboux, 

 Hilbert, Klein, Lorentz. Mittag-Leffler, Newcomb, Picard, 

 Poincar^, Veronese, and Volterra. Full particulars of the 

 congress can be obtained from the general secretary. Prof. 

 I.. Castelnuovo, 5 Piazza S. Pietro in Vincoli, Rome. 



Referring to the letter by the Rev. John J. Hampson 

 in our issue for January 30 (p. 295) dealing with " stock 

 frost " or ground ice, .Mr. D. O. S. Davies, of the Norwich 

 Technical Institute, reminds us of a volume on the 

 subject of " Ice Formation, with Special Reference to 

 .\nchor-ice and Frazil," by Prof. H. T. Barnes, of Mc(iiU 

 University, Montreal. Prof. Barnes provides information 

 on the points raised by Mr. Hampson in his letter. The 

 book, a descriptive review of which appeared in the issue 



NO. 1997, VOL Jj] 



of Nature for January 17, 1907 (vol. Ixxv., p. 267), is 

 published in this country by Messrs. Chapman and Hall, 

 Ltd. 



The Souih-Eastern Gazette of January 28 contains an 

 obituary notice of the late Mr. Edward Bartlett, who from 

 1875 until 1890 occupied the post of curator and librarian 

 of the Maidstone Museum. The deceased naturalist was a 

 son of the late Mr. A. D. Bartlett, the well-known super- 

 intendent of the Zoological Society's menagerie in the 

 Regent's Park. In his earlier years Mr. Bartlett travelled 

 as a natural history collector in Upper .Amazonia, where 

 he obtained many valuable specimens. Later on, 1863-4, 

 he accompanied the late Canon Tristram to Syria and 

 Palestine, and in 1891 left Maidstone for Sarawak, to 

 act as curator of Raja Brook's museum, a post which he 

 occupied until 1897, when he returned home. Mr. Bartlett 

 edited his father's well-known work " Wild Animals in 

 Captivity," and was himself the author of several papers 

 on natural history subjects. 



No. 13 of the Bulletin of the Imperial .Academy of 

 Sciences of St. Petersburg for 1907 contains a paper, un- 

 fortunately in Russian, by Mr. D. Dejneka, on the nervous 

 system of the nematode worms. 



We have received copies of two papers published by the 

 author at Lancaster, Pa., as Nos. i and 2 of a new serial, 

 Weber's Archives, in which the author, Veterinary-Surgeon 

 Weber, claims to have bred from the eggs of the ordinary 

 gnat, Ctilex pipiens, two other species of gnats or mosqui- 

 toes, in addition to the normal progeny. " Mutation in 

 Mosquitoes " is the title of the second and larger paper. 

 The earlier one, which contains a preliminary account of 

 the same alleged phenomenon, is a reprint of an article 

 published two years ago in Natur tind Haus, vol. xv.. 

 May, 1907. 



Two papers on the reproductive organs of sharks have 

 recently appeared within a short time of one another. 

 The first, by Mr. Albert Krall, is published in vol. xxxvii., 

 part iv., of the Morphologisches Jahrhuch, and devoted 

 specially to the " claspers " on the pelvic fins of the male 

 of Hexanchus griseus, and generally to the corresponding 

 organs in other sharks. In the second, which appears in 

 vol. xxxviii., part iv., of the Zeitschrift fiir wisseii- 

 schaftliche Zoolugie, Dr. Victor Widakowich describes the 

 uterus of the spinv dog-fish l_Squahts acanthias), with re- 

 marks on the developmental history of allied species. The 

 structure of the uterus is described in great detail, and a 

 figure given of a portion of its wall containing an embryo. 



CoNSiDER.'iBLE interest attaches to an account by Mr. 

 C. H. Danforth, published in vol. xxxiv., No. i, of the 

 Proceedings of the Boston Society of Natural History, of 

 a new genus and species (_PaedocUone doliiformis) of 

 pteropod mollusc from Casco Bay, Maine. The new form, 

 which was taken in plankton, " does not properly fall 

 under any established family, although perhaps it 

 approaches most nearly the Clionid;e, from which it differs 

 in having an odd number of cephalocones and the entire 

 posterior part of the body filled by the viscera." In life 

 the creatures swam for some time by means of their fins, 

 and then sank for a time below the surface, after which 

 the swimming was resumed. With the exception of 

 numerous vacuoles in the integument filled with yellowish 

 or yellowish-brown fluid, the body is transparent. 



The distribution of the pine-marten in England and 

 Wales forms the subject of an article by Mr. H. E. Forrest 

 in the January number of the Zoologist. In the midland 



