February 9, i 



NA TURE 



further, that it is purely adaptive, being calculated to maintain a 

 due proportion between the length of the centrum and the width 

 of the body, without diminishing the length of the muscle- 

 segments. — Mr. George Murray, F.R.S. , and Miss F. G. 

 Whitting (Newnham Coll., Camb.) communicated a paper on 

 new Peridiniacete from the Atlantic, of which (in the absence of 

 Mr. Murray through indisposition) an abstract was given by the 

 Secretary. — Mr. A. J. Maslen read a paper on J.epidostrobits 

 After remarking that the late Prof. Williamson's collection of 

 fossil plants in the Natural History Museum contained a number, 

 of slides which he had associated with Lcpidostrobus, but which 

 could not be referred with certainty to the particular vegetative 

 organs to which they belonged, while it was difficult also to 

 refer isolated sections of the same type of Strobilus to one 

 another, he explained that the present paper gave the result of 

 a re-e.xamination of Williamson's slides of Lcpidostrobus, under- 

 taken at the suggestion of Dr. D. H. Scott. His object and 

 endeavour had been to make out, if possible, at least some 

 distinct forms ; but he had found great difficulty in determining 

 whether the observed structural differences in isolated sections 

 were really of specific value or not. He considered it safer to 

 adopt Williamson's Ltpidostrobtis Oldhami for a common type 

 of structure, and by comparison to describe three marked vari- 

 ations (a, /3, and 7). A clearly distinct form he described as a 

 new species under the name Lepidostrobtts foliaceics. 



Entomological Society, January 18. — Annual Meeting. — 

 Mr. Roland Trimen, F.R.S. , President, in the chair.— It was 

 announced that the following gentlemen were elected as officers 

 and Council for 1899 : — President, Mr. G. Pl.Verrall ; Treasurer, 

 Mr. R. McLachlan, F.R.S. ; Secretaries, Mr. J. J, Walker and 

 Mr. C. J. Gahan ; Librarian, Mr. G. C. Champion ; and as 

 other members of Council, Mr. W. F. H. Blandford, Dr. T. 

 A. Chapman, Mr. H. St. J. K. Donisthorpe, the Rev. Canon 

 W. W. Fowler, Mr. A. H. Tones, Mr. F. Merrifield, Mr. E. 

 Saunders, Mr. R. Trimen, F'.R.S., Mr. J. W. Tutt and Mr. C. 

 O. Waterhouse. — The address of the retiring President was then 

 read by the Secretary. In this, after a review of the present 

 position of the Society, an account was given of the various ex- 

 perimental researches and observations made on the subject of 

 seasonal dimorphism in lepidoptera from those of Weismann 

 down to the evidence recently brought forward by Dr. Dixey on 

 the existence of this phenomenon in Neotropical Pierinre. 



Manchester. 

 Literary and Philosophical Society, January 24, — Mr. 

 J. Cosmo MelviU, President, in the chair. — The President 

 announced that the Council had awarded the Wilde Medal of 

 the Society for 1899 to Sir Edward Frankland, K.C.B., F. R..S., 

 and the Wilde Premium of fifteen guineas to Dr. Charles H. 

 Lees. The presentation of the medal and premium had been 

 fixed for February 28, when the Wilde Lecture would also be 

 delivered by Prof. William Ramsay, F.R.S. — Dr. F. H. Bow- 

 man stated that he had recently seen a specimen of wheat grown 

 in South Africa, consisting of about 420 stalks which were 

 apparently produced from a single seed ; each stalk had an ear 

 containing on the average forty grains. The President and Mr. 

 Charles Bailey agreed that the plant was most probably Tritiium 

 composilum, and Mr. Tristram stated that plants bearing 190 

 stalks had been grown in Lancashire. — The President exhibited 

 specimens ai Eichhornia speciosa, Kunth (the water hyacinth), 

 and Btititm virgatuiii, L. (the strawberry blite), and also a series 

 of leaves of the common holly (Ilex ai/uifoliiim, L. ) showing 

 every kind of variation. — Mr. Charles Bailey explained the 

 structure of the peculiar permanent sheath which encloses the 

 extremity of each root and looiXeX. oiihe Fonledcria (Eich/ionna) 

 crassipes. The specimens exhibited to the members under the 

 microscope showed that these sheaths were like the long finger 

 of a glove in shape, and varied in size according to the age of 

 the organ. The organic connection between the root and its 

 sheath is found at the extremity of the root at the bottom of the 

 sheath. The sheaths are of fair consistency, and are doubtless 

 designed for the protection of the plant, which, by means of its 

 inflated leaf-stalk, passes its life floating upon the surface of the 

 water ; the growing and tender extremities of the root are in this 

 way guarded against the attacks of the smaller aquatic animals. 

 The species of the cryptogamic genus Azolla, which also pass 

 their existence in a floating condition, have a very similar root- 

 sheath, but in their case the organ is only temporary, being 

 discarded before the root reaches maturity. 



NO. 1528, VOL. 59] 



Paris. 

 Academy of Sciences, January 30. — M. v.an Tieghem in 

 the chair. — Remarks by M. Kaye on vol. i. of the Annales de 

 I' obseri'atoire de Nice. — Observation of the B-group in the 

 solar spectrum, made at the summit of Mont Blanc, by M. A. 

 de la Baume-Pluvinel. Photographs of the solar spectrum at 

 Paris, Chamonix, and the summit of Mont Blanc, show that the 

 group of B lines still remains at the highest elevation, but with 

 an intensity much less than in the lower layers of the atmosphere. 

 — Remarks on the preceding communication, by M. Janssen. — ■ 

 On the generalisation of the first method of Jacobi, by M. N. 

 Saltykow. — On groups of the class N - « and of degree N, 

 transitive not less than n - I times, by M. Edmond Maillet. — 

 On the problem of iteration, by M. Lemeray. — On the pro- 

 longation of analytical functions, by M. Emile Borel. — On ortho- 

 gonal systems, by M. A. Pellet. — Doubly cylindrial surfaces and 

 isothermal surfaces, by M. L. Raffy. — On surfaces of total con- 

 stant curvature, by M. Tzitzeica. — On the lines of curv- 

 ature of certain surfaces, by M, Blutel. — On curves of 

 traction, by M. H. Bouasse. — Permanent torsion and the 

 point of recalescence in steel, by M. G. Moreau. It 

 is shown that for wires of dift'erent diameters with a 

 sufficiently large initial torsion, the relation between the residual 

 torsion T,., the torsion T, and the diameter d, is given by 

 Tr=T - kid. Measurements of k for a well tempered steel wire 

 raised to diff'erent temperatures by means of an electric current, 

 showed that k remained constant up to about 300°, and then 

 slowly diminished up to the point of recalescence, 715°, after 

 which it remained constant. — Double refraction produced by 

 the magnetic field related to the Zeeman phenomenon, by M. 

 A. Cotton. In a previous paper it has been shown that the pro- 

 duction of a magnetic field affects the optical properties of 

 sodium vapour and nitrogen peroxide. An analysis of the light 

 which reappears under the action of the field now shows that 

 the explanation originally suggested is correct ; for each of the 

 new rays created by the field, the flame absorbs from the ray of 

 white light only those vibrations identical with those it emits 

 itself. — On the transparency of opaque bodies for luminous 

 radiations of great wave-length, by M. Gustave de Bon. With 

 a lamp wrapped in black paper, objects placed in an opaque box in 

 contact with a phosphorescent zinc sulphide screen could be photo- 

 graphed. — On the differences existing between X-rays proceeding 

 from one body, by M. G. Sagnac. The bundle of secondary rays 

 emitted by a heavy metal exposed to X-rays, consists of rays of 

 very different penetrative power, in every case less than that of 

 the original rays. — The explosive power of acetylene at very low 

 temperatures, by M. Georges Claude. The solubility of acetylene 

 in acetone increases very rapidly as the temperature diminishes, 

 acetone at - 80° dissolving more than 2000 volumes of the gas. 

 A platinum wire may be kept at a red heat in this solution with- 

 out any explosion taking place. Liquid acetylene at - 80" be- 

 haves similarly. — On the alloys of iron and nickel, by M. F. 

 Osmond. A series of iron-nickel alloys was prepared, con- 

 taining only small amounts of manganese and carbon, and in 

 which the nickel varied in amount from o"27 to 98 '5 per cent. 

 These alloys were heated, and the temperature at which their 

 magnetic properties vanished noted : the curve showing the re- 

 sults has three branches, showing maximum transformation 

 temperatures at o, and 70 per cent, of nickel. — On the de- 

 composition of carbon monoxide in presence of metallic oxides, 

 by M. G. Boudouard. Carbon monoxide was passed over the 

 oxides of nickel, cobalt, and iron, at 445°, and the rate of re- 

 duction measured. If the time of heating is sufficiently 

 prolonged the decomposition is total with the oxides 

 of nickel and cobalt.— On a new method of estimat- 

 ing carbon monoxide, by MM. Schlagdenhauften and 

 Pagel. Carbon monoxide completely reduces silver oxide at 

 60°, cuprous oxide at 2I5'-300°, and hence these oxides may be 

 used to estimate the gas. — On some aromatic iodo-ketones, by 

 M. A. Collet. A description of the preparation and properties 

 of iodo-acetophenone, CsHj.CO.CH.J, and the corresponding 

 CH3.CeH4.CO.CHJ, and CHs.CeHj.'CO.CHI.CHa.— Remarks 

 on the preparation of the oxyethylamines, by M. F. Chancel. 

 By the action of ammonia upon glycol chlorhydrin, the chlorhy- 

 drate of trioxyethylamine is readily obtained in a pure state. — E.x- 

 traction and synthesis of the perfume of the jasmine flower, 

 by M. Albert Verley. Preliminary attempts to isolate the 

 essence by distillation with steam having failed, the perfume was 

 taken up by fat in the usual way. This extracted with heavy 

 petroleum oil and acetone gave only 40 gr., 90 per cent, of which 



