142 



NA TURE 



[December 8, 1898 



exhibited and made remarks on some bird remains which had 

 been obtained from excavations at the Lake-dwellings near 

 Glastonbury, Somersetshire, and among which were numerous 

 bones of a I'elecan. — Mr. Oldfield Thomas read a letter which 

 he had received from Seizor Ameghino on the subject of the 

 newly discovered maminal Neomyhdoii, ^wmg further inform- 

 ation, obtained from the Indians, as to its distribution, characters, 

 and habits.— A communication was read from Dr. E. A. Goeldi 

 on the .\mazonian Lepidosiren, in which he recorded the capture 

 of two further examples of thisDipnoan in the island of Marajo. 

 Dr. (Soeldi gave a short description of the physical features of 

 the locality in which he had found Lepidosiren — a " pirisal " 

 or papyrus-meadow. He also referred to the live specimen in 

 his aquarium which had recently developed branches on its fore 

 limbs. Dr. Goeldi pointed out the gill like character of the 

 fore limb, and adduced it as a support to the Gegenbaur theory 

 of limbs, lie also suggested the possibility that the so-called 

 fore limb of Lepidosiren is not a true fore limb, but a persistent 

 external gill. This paper was illustrated by the exhibition of 

 three specimens of the Amazonian Lepidosiren, which Dr. 

 Goeldi had forwarded for presentation to the British Museum. — 

 Mr. F. G. Parsons read a paper on the anatomy of adult and 

 foetal specimens of the Cape Jumping Hare (Pedetes caffer). In 

 it the different systems— osseous, muscular, nervous, circulatory, 

 digestive, &c. — were described in some detail, and contrasted 

 with the corresponding parts in two Jerboas (Dipiis /lirli/'es 

 and D. jerboa). — A communication was read from Mr. F. O. 

 Pickard-Cambridge on a small collection of spiders from 

 Trinidad, West Indies. .Specimens of six species were con- 

 tained in the collection, of which three were described as 

 new. — .Mr. W. E. de Winton read some notes on the breedmg 

 of a female African Wild Ass (Eqiius asiiuis) in the Society's 

 gardens, and called attention to certain facts as regards 

 her offspring, which gave some support to the doctrine of 

 telegony. — Mr. de Winton also read a paper describing the 

 moulting of the King Penguin (Aptenodyles pitmanti), as 

 observed in a specimen in the Society's gardens. The author 

 remarked that the specimen in question had lived in the gardens 

 for sixteen months, and during that period had moulted only 

 once. — A communication was read from Dr. A. G. Butler on a 

 collection of butterflies made at Salisbury, Mashonaland, in 

 1898, by Mr. Guy .\. K. Marshall. The collection contained 

 specimens of sixty-five species, which were enumerated. Two 

 new genera {'/'orynesis and Tarsocera) and one new species 

 (Aslanga marshaili) were described in the paper. — Mr. G. A. 

 Boulenger, F. R.S., read a third report on the additions to the 

 Lizard Collection in the Natural History Museum, containing a 

 list of this cl.iss (165 in number), new or previously unrepre- 

 sented, of which specimens had been added to the collection 

 since 1894. 



Cambridge. 



Philosophical Society, October 31.— Annual General 

 Meeting. — Mr. F. Darwin, President, in the chair. — The fol- 

 lowing were elected officers for the ensuing year : — President, 

 Mr. J. Larmor. Vice-Presidents : .Mr. Y. Darwin, Prof. For- 

 syth, Dr. Gaskell. Treasurer : Mr. Shipley. .Secretaries : Mr. 

 Newall, .Mr. Bateson, Mr. Baker. Members of Council : Mr. 

 H. Gadow, Mr. D. Sharp, Prof. J. J. Thomson, Mr. A. Berry, 

 Mr. Wilberforce. — On the evaluation of a certain determinant, 

 which occurs in the theory of statistics and of elliptic space, by 

 Mr. A. Berry. — (I) .Metrical relations between linear complexes, 

 by Mr. J. H. Grace. In this paper are discussed the metrical rela- 

 tions which exist between the mutual moments and pitches of sys- 

 tems of four, five and six linear complexes. Some of the results are 

 applied to a geometrical representation of a four-system of 

 screws. (2) Apolar systems of quadrics. — Certain systems of 

 quadratic complex numbers, by Mr. A. E. Western. — On Mittag- 

 Lelller's theorem, by Mr. 11. F. Baker. — The connection be- 

 tween the chemical constitution of a gas and the ionisation pro- 

 duced in it by Ronlgen rays, by Prof. J. J. Thomson. The 

 measurements of the ionisation produced by Rontgen rays in 

 fourteen gases showed that the ionisation was connected with 

 the chemical composition in a very simple manner. The 

 ionisation was found to be an additive properly. — On con- 

 vection currents, and on the fall of potential at the elec- 

 trodes in conduction produced by Rontgen rays, by Mr. J. 

 Zeleny. During conduction through a gas exposed to Rontgen 

 rays, convection currents arc set up in the gas. When two 

 parallel, ])lane electrodes are used, the motion of the gas begins 



NO. I 5 19, VOL. 59] 



symmetrically from the centre towards each of the plates. The 

 motion is conveniently made visible by particles of ammonium 

 chloride formed in the gas from ammonia and hydriKhloric acid. 

 Screening from the rays the space next to one of the electrodes 

 mcrea.ses the strength of the convection currents on that sid< . 

 The cause of these currents is attributed to the motion through 

 the gas near the electrodes of an unequal number of the twokimk 

 of ions by means of which the conduction takes place. — On 

 velocity of solidification, by Mr. II. .V.Wilson. The relation 

 between the velocity of solidification of a super-cooled liqui 1 

 and the super-cooling has been investigated for a number of sul 

 stances by G. Tammann and Friedlander (Zeilschrifl P. C. , 

 xxxiv. p. 152, 1897, and xxiii. p. 326, 1897). Assuming tha 

 the rate of solidification is directly proportional to the differenc ■ 

 between the internal pressures in the liquid and solid and in 

 versely proportional to the viscosity of the liquid, the velocity of , 

 solidification can be expressed by a simple formula. 



November 28. — Mr. J. Larmor, President, in the chair. 

 — (a) On the flame spectrum of mercury and its bearing 

 on the theory of the distribution of energy in gases, by Prof 

 Liveing. The author had found that mercury healed in 

 a flame of cyanogen, burning in oxygen, emitted at least 

 two rays, at wave-lengths 2535 and 4358, which he had been 

 able to photograph. The vibrations producing these rays 

 must, he thought, be the result of a direct change of heat into 

 vibratory energy : and if so, the ratio of the specific heats of 

 mercury, at constant pressure and constant volume, proved only 

 that, at the temperature of the compressed vapour in a sound 

 wave, no very sensible proportion of the heat is converted into 

 vibratory motion, though at a higher temperature a sensible 

 proportion is so converted. This appears to negative the hypo- 

 thesis that energy is always distributed equally in all the degrees 

 of freedom of the molecules, as well as the assumption that a gas 

 having I •66 for the ratio of its specific heats must have mon- 

 atomic molecules, (b) On the variation of intensity of the 

 absorption bands of diff'erent didymium salts dissolved in water, 

 and its bearing on the ionisation theory of the colour of solutions 

 of salts. The author exhibited a series of photographs of the 

 ab.sorption bands produced by equivalent solutions of didymium 

 nitrate and chloride, of which the strength was regularly graded, 

 and the absorbent thickness varied. — Note on the vapour of 

 iodine, by Prof. Dewar. The author had found that by careful 

 distillation in vacuo films of iodine could be made so thin as to 

 transmit light and exhibit the colours of thin plates by reflection. 

 He exhibited experiments showing that at ordinary temperatures 

 pure dry iodine emits vapour which, in a half-litre flask contain- 

 ing air, is sensibly coloured, whereas in similar circumstances, 

 except that the air pressure was reduced, the colour is much 

 less. This diflerence is enhanced as the temperature rises, so 

 that at 100^ it is very marked in a tube of only i cm. diameter. — 

 On the partitions of numbers which possess symmetrical graphs, 

 by Major Macmahon, F. K.S. 



MANrm-.SlER. 



Literary and Philosophical Society, November 15. — 

 Mr. J. Cosmo Melvill, President, in the chair. — Dr. G. H. 

 Broadbent described the development and life-history of 

 Voiiicetia pulriiia by means of thirty-four diagrams made from 

 his own investigations. The cyst is circular in shape, the 

 contents being finely granular, and the only indication of life is 

 given by the contractile vesicle. This at first contracts at rare 

 intervals and very slowly, and after a lime an oral canal 

 appears which gradually becomes more distinct, whilst the con- 

 tractions of the vesicle grow more frequent. When the vorlicella 

 emerges from the cyst, a small portion is at first protruded 

 through a very small aperture in the cyst-wall, in shape like a 

 bladder, this gradually increasing in size until the whole creature 

 has emerged, the aperture meanwhile appearing not to increase 

 in the least. It is remarkable that after full extrusion the cyst- 

 wall remains as large and as circular as before, whilst the 

 organism is much larger than the cyst, and the vesicle greatly 

 increased in size, thus indicating that the creature has been 

 under great prcs.sure in the cell. After emerging, the vorticella 

 may remain (juiescent for a lime, until the basal cilia are 

 developed, when it swims rapidly away as a " free-swimming" 

 form. It afterwards attaches itself by the basal portion In 

 some foreign body, and begins to shoot out a stalk which 

 increases in length, while cilia are developed at the oral end. 

 "Detached" as distinguished from "free-swimming" forms 



