I30 



NA TURE 



[June 9, 1904 



refraction of air to the density. It appears that the index 

 of refraction increases more rapidly under pressure than is 

 ■consistent with the law (»— i);'d = constant, whereas the 

 vtlue of (»■— i)/(n-+i)ii is practically constant except at 

 low pressures, where the observations could not be made 

 with a great degree of accuracy. 



Dr. SrfpHANE Leduc, of Nantes, has communicated to 

 the French Physical Society a note on crystal formation, 

 advancing the hypothesis that the phenomenon of crystal- 

 lisation depends not only on the arrangement of the mole- 

 cules in geometric forms, but also on the movement of 

 these molecules through the liquid in certain regular and 

 geometric directions. This hypothesis is based on the 

 author's observations on crystallisation in liquids thickened 

 by colloids. 



It is well known that two triangles in the same plane 

 may be homologous in i, 2, 3, 4 or 6 different ways at 

 the same time, and that two tetrahedra may be homologous 

 in I, 2 or 4 different ways, it being assumed in either case 

 that there are no common vertices. Prof. Luigi Berzolari 

 contributes a note to the Atii dei Lincei, xiii. (i), 9, in 

 which it is shown that in space of more than three 

 dimensions two pyramidoids cannot have more than one 

 centre of homology unless they possess common vertices or 

 corners. 



The results of meteorological and magnetical observations 

 made at Stonyhurst College Observatory during 1903 have 

 ■been published in the usual concise form, with the excep- 

 tion of the valuable appendix containing the Malta meteor- 

 ological returns. Father Sidgreaves states that the year 

 will be known as the wet year, the rainfall being ii-8 

 inches above the annual average. Notwithstanding the un- 

 favourable weather, the solar surface was observed on 207 

 ■days, and 141 plates have been added to the collection of 

 stellar photographic spectra. 



We have received from the Deutsche Seewarte part xii. 

 of Ueberseeische meteorologische Beohachtungen, contain- 

 ing carefully made observations, three times a day, at the 

 following remote localities : — Marshall Islands (two 

 stations), Nauru (lat. 26° S., long. 167° E.), Apia (Samoa), 

 Tsingtau (lat. 36° N., long. 120° E.), and Rarotonga 

 (Cook's Islands). With the exception of the latter station, 

 all the observations were taken at the German colonies in 

 ■the Pacific Ocean. It is worthy of note that the prepar- 

 ation of this very valuable work has been financially sup- 

 ported by the Colonial Department of the German Foreign 

 Office. 



Capt.mn D. Wilson B.arker, in his presidential address 

 ■to the Royal Meteorological Society, reviewed the past and 

 present condition of ocean meteorology. The importance 

 of this branch of science led to the international conference 

 on meteorological observations at sea at Brussels in 1853, 

 and to the establishment of the Meteorological Department 

 of the Board of Trade by Mr. Cardwell in the following 

 year, under the superintendence of Captain (afterwards Vice- 

 Admiral) FitzRoy. He and Captain Maury in the United 

 States (more especially the latter) are recognised as the 

 most successful pioneers of ocean meteorology. Maury con- 

 structed wind and current charts for all oceans, copies of 

 which were supplied gratuitously for the use of navigators 

 in this country, and FitzRoy and his sniall staff at once 

 set to work on them, and converted the pilot charts (which 

 showed the wind directions numerically under each principal 

 point of the compass) into graphical " wind-stars," and 

 ■subsequently (about 1859) FitzRoy commenced the publi- 

 NO. 1806, VOL. 70] 



ration of a new series of monthly (instead of quarterly) 

 charts, including wind-force and other data obtained from 

 log-books collected by the Board of Trade Department. 

 Other countries, especially France, Germany, and Holland, 

 also pursued the subject vigorously ; the Deutsche Seewarte 

 published, among numerous other valuable works, an atlas 

 of thirty-six charts of the Atlantic Ocean. In 1874 another 

 international maritime conference was held in London, and 

 was attended by representatives of all the principal nations. 

 In this country the .Meteorological Council, with the cooper- 

 ation of the Hydrographic Office of the Admiralty, continues 

 to devote untiring attention to this important subject. 

 Captain Barker's able summary is contained in the 

 Quarterly journal of the Royal Meteorological Society for 

 April last, and is illustrated by maps drawn on Flam- 

 steed's projection, showing very clearly the principal 

 meteorological elements, five or six maps being devoted to 

 each of the great oceans. 



We have to acknowledge the receipt from the Field 

 Columbian Museum, Chicago, of copies of three papers on 

 manimals by Dr. D. G. Elliot, published last year. 



We regret to find that in the notice of Mr. Regan's paper 

 on the classification of fishes in our issue of June 2 

 (p. loq), the Teleostei are stated to be derived from the 

 Chondropterygii instead of from the Chondrostei. 



According to a well illustrated article in the March 

 number of the American Naturalist by Prof. E. A. Andrews, 

 the assumption that the breeding habits of the American 

 crayfish are identical with those of its European relative 

 proves to be incorrect, and it turns out that there are con- 

 siderable differences in this respect between the two species. 

 The second article in the same issue, by Mr. W. M. Small- 

 wood, is devoted to the natural history of the bulla-like 

 mollusc known as llainiiica solitaria. 



All recent experiments on keeping animals in menageries 

 in the open air seem to point to the superiority over the 

 old plan of confining them in close and narrow cages. 

 In the report of the Zoological Society of Philadelphia for 

 1903, for instance, it is stated that the raccoons in the 

 society's menagerie were recently placed in an open en- 

 closure containing a tall tree with a cavity at the base, and 

 a hollow log. With these natural retreats at hand, it is 

 noteworthy that the raccoons preferred to pass their time 

 in winter, even during most inclement weather, high up in 

 the tree, some 40 or 50 feet above the ground. In the same 

 report the importance of pathological investigations into the 

 causes of death of animals dying in menageries is urged. 



The Australian Ornithologists' Union is to be congratu- 

 lated on the completion of the third volume of its official 

 organ, the Emu. Efforts are to be made in the immediate 

 future to render this valuable journal more strictly scien- 

 tific. The part before us contains a coloured plate of two 

 species of honey-eater, which, although described many 

 years ago, have never previously been figured. 



.'\ccoRDiNG to the report for 1903, there is a satisfactory 

 and continuous increase in the amount of gate-money taken 

 at the Giza Zoological Gardens, the receipts for that year 

 being ;^i2i3 (Egyptian), against .^^1037 in 1902. An ex- 

 tremely interesting feature in the report is the notes on 

 the habits of the numerous species of Nile fishes kept in the 

 aquarium. From these it appears that the proboscis-fish 

 {Morntyrus kannume) is chiefly nocturnal, and employs its 

 long snout in probing about among stones for animal food. 



