88 



NA TURE 



[May 23, 1 901 



We are indebted to the president of the International 

 Aeronautical Committee for the following preliminary results of 

 the balloon ascents on April 19. The number of balloons was 

 19, of which 6 were manned, and the countries that participated 

 in the investigation were Austria, France, Germany and I-iussia. 

 The results of the manned ascents from Berlin and Vienna were 

 remarkably coincident : Berlin, temperature at starting, 5'''6 C, 

 and -25°'5 at an altitude of 5500 metres; Vienna, 5°'o at 

 starting, and - 25°'o at 5260 metres. The greatest heights 

 attained by the unmanned balloons were : 10,500 metres at 

 Strassburg, temperature -54": n,ioo m. at Trappes (near 

 Paris), temperature- 62' ; 11,848 m. at Chalais-Meudon, tempe- 

 rature -52°'8C. The only instance in which an inversion of 

 temperature was recorded appears to have been at Strassburg, 

 but the balloon, which was made of paper, burst at an altitude 

 of 1500 metres. 



A GENERALISATION of Clairant's form in the theory of dif- 

 ferential equations of the first order, based on certain considera- 

 tions given by Raffy, is contained in a note by Signer Minea 

 Chini in the Kendicoitto del R. Istituto Lombardo, xxxiv. 8. 

 In this note the author examines what are the types of differen- 

 tial equations of the first order in .v, y whose general integrals 

 are obtainable by replacing the differential coefficient / in the 

 original differential equation by a previously determined function, 

 (i.) of .V, C, (ii.) of .1', y., C, where C is an arbitrary constant. 



A SHORT note on the propagation of Filaria iminites by the 

 agency of mosquito bites is contributed by Signor G. Noe to the 

 Atti dei Lincei, x. 8. It has now been conclusively proved that the 

 filariiT^ of the blood are transmitted from one host to another by 

 mosquitoes which act as intermediate hosts. An experiment, in 

 which a healthy dog was madejto eat hundreds of Anopheles, 

 both from infected regions and others infected in a laboratory, 

 without itself becoming infected, excludes the possibility of the 

 parasites being propagated otherwise than by punctures. 



The Transactioiii and Anntia! Report of the Manchester 

 Microscopical Society for 1900 bears ample testimony to the 

 flourishing state of that institution and the keenness of its 

 members for hard work. The address of the president. Prof. 

 S. J. Hickson, deals with the reproduction and life-history of 

 the Protozoa, special attention being directed to recent investi- 

 gations on that group and the alteration in our views thereby 

 rendered necessary. It is now inexact to say that the Protozoa 

 are, as a general rule, animals of simple constitution, many of 

 them being, to a certain extent, specialised. Among other 

 papers, Mr. M. L. Sykes contributes an exceedingly interesting 

 article on smallpox and vaccination, and the mode of producing 

 glycerine cultivations of vaccine lymph, which may be com- 

 mended to the best attention of anti-vaccinationists. 



The two issues (Nos. 9 and 10) of the Biologiuhcs Ccnli-al- 

 blatt for May contain ai tides dealing with the freshwater inver- 

 tebrate fauna of Lake Baikal. In No. 9 Herr W. Zygoff 

 discusses the sabellarian annelid from the lake described by 

 Prof. J. Nusbaum in the same journal for January I as the first 

 known freshwater member of its group under the name of 

 Dybowscel/a baicalensis. It is pointed out that a North American 

 freshwater form, A/aiiayunkia speciosa, was described long ago 

 by Leidy, and it is urged that the one inhabiting Lake Baikal is 

 inseparable. In the following article Prof. Nusbaum disputes 

 this identification, alleging that while Manayunkia is herma- 

 phrodite, in Dybowscella the sexes are distinct. No. 10 

 contains a general article on the fauna of the lake by Herr A. 

 Korotneff, in which a new freshwater polyzoan is described as 

 Echinetla placoidcs. 



Under the title of "A Theory of the Origin and Evolution 

 of the Australian Marsupials" Mr. B. A. Bensley, in the April 

 NO. 1647, VOL. 64J 



number of the American Naturalist, publishes a further account 

 of the result of his investigations into the history of that group. 

 Starting with the well-known fact that the group simulates most 

 of the placental orders, the inference is drawn that its evolution, 

 or "radiation,"' has taken place within its present habitat, 

 Reasons are then given for regarding the banded anteater 

 (Myrmecobius) as a degraded type ; and if this view be 

 accepted, all the other types can be derived, both as regards 

 their dentition and their feet, from the American opossums, the 

 ancestors of which are regarded as the progenitors of the whole 

 group. All the Australian marsupials thus appear to have had 

 an arboreal ancestry ; and when, in spite of the specialisation of 

 certain forms, the primitive character of the whole group is 

 borne in mind, it seems evident that the date of the " radiation " 

 is comparatively recent. Hence the author is inclined to side 

 with those who consider that marsupials first entered Australia 

 during the Tertiary period, although he thinks their arrival was 

 later than has previously been considered possible. As to 

 whether their immigration was from the north or from the south 

 he is undecided, although he states that " there is at least some 

 justification for the view that it was from the northward," i.e. 

 by way of Asia. 



During his travels in Southern India (1S16-20), with a view 

 to the economic development of Pondicherry and other French 

 possessions in the East, Leschenault de la Tour made a valu- 

 able collection of rocks, which are preserved in the Museum of 

 Natural History in Paris. Some of the rocks, pyroxenic and 

 scapolitic gneisses, were described in 1889 by Prof. A. Lacroix, 

 but as their geological relations had not been determined, Mr. 

 T. H. Holland, of the Geological Survey of India, has specially 

 examined the entire collection in Paris, and has also investigated 

 the area from which the rocks were obtained. His observations 

 are recorded in an article on the geology of Salem, Madras 

 Presidency {Mem. Geo!. Siirv. India, vol. xxx. part 2, 1900). 

 The rocks which he describes are, in probable order of age, (l) 

 fundamental biotite-gneisses ; (2) schists; (3) pyroxene-granu- 

 lites ; and (4) younger igneous intrusions, including basic dykes, 

 peridotites and "white elephant" rocks — masses of quartz having 

 the characters of plutonic quartz and containing much liquid 

 carbonic acid. 



In the'' May issue of the Cambrian Natural Observer, Mr. 

 Arthur Mee directs attention to the state of the grave of the 

 Rev. T. W. Webb, author of the classical " Celestial Objects 

 for Common Telescopes," in the churchyard of Mitchel Troy, 

 near Monmouth. There is no reference on the stone to indicate 

 the invaluable work accomplished by Webb, and Mr. Mee sug- 

 gests that some means be adopted of suitably recording the 

 services rendered to astronomy by the deceased divine. 



The peculiar thermal properties of the alloys of nickel and 

 steel discovered by M. C. E. Guillaume have already met with 

 more than one application, the existence of an alloy with a 

 practically negligible coefficient of expansion pointing to an ideal 

 material for the construction of length standards for geodesic 

 measurements. In the current number of the Comptes rendtis 

 is described a further application by M. Guillaume of this 

 material. The secondary compensation error of a chronometer, 

 discovered by Dent in 1833, is due to the fact that a chrono- 

 meter adjusted for two fixed temperatures is not perfectly 

 adjusted for any other temperature. In the present paper, it is 

 shown that by the use of a suitable nickel-steel alloy it is possible 

 to compensate perfectly the variations of elasticity of the spring 

 with a balance of the ordinary form. 



The same number of the Comptes reitdus contains an impor- 

 tant communication by M. Jean Friedel to the theory of chloro- 

 phyll assimilation. It is usually held that three conditions are 



