346 



NATURE 



[May 13, 1920 



Societies and Academies. 



London, 

 Royal Society, April 29.-Sir J. J. Thomson, presi- 

 dent, in the chair.— Prof. J. W. Gregory: The Irish 

 eskers. Eskers are banks of sand and gravel, typically 

 occurring as ridges on the central plain of Ireland, 

 where they were deposited during the recession of the 

 ice at the close of the Glacial period. They have been 

 generally attributed to deposition along glacial rivers 

 Ike Swedish osar. Their structure and composition 

 indicate that the most important Irish eskers were 

 fornied along the margin of the receding ice-sheets 

 by floods of water, due to the melting of the ice 

 Irish eskers formed along glacial rivers are relativelv 

 small and exceptional. The accumulation of the 

 materials into ridges, and their restriction between 

 about ISO ft. and 300 ft. above sea-level, are attributed 

 to the formation of the eskers where the ice entered 

 into a sheet of water, which was probably the sea 

 since marine fossils are widely distributed in the 



miSn t7^*-',Tf '^"^^ ^'■^ "° embankments to 

 maintain glacial lakes at the required level. It is 

 proposed that the term "esker" should be continued for 



?n cl'-f 7"^ "T"'^' °^ '^"^ ^"d g^^^eJ' but that 

 in glacial geology the term - osar - should b^ used for 

 ridges formed along the course of glacial rivers, and 

 kame for ridges deposited by water along the 

 margin of an ice-sheet.— Miss K. M. Curtis -Thl life 



T^h i-^''^'u- r'^-' *^^ ''^"^ °f w^''* disease in potato, 

 folln, Ih^k '^''t"'^n-'^^?°Sy°^ the organism have been 

 followed through all their stages. In the course of 

 the investigation the following important points have 

 been determined : (i) A sexual process has been dis- 



oT^fh^ H"ff ^"""^^"i ^" ^" ''' ^^'^^'' (^) the nature 

 of the difference between the resting (or winter) 



fK-Si^^"? the sori (or summer sporangik) has been 

 established; (3) the infection of the host-tissue by the 

 zoospores and zygotes has been traced; and (4) the 

 peculiarities in the behaviour of the nucleus of the 

 parasite have been investigated.— B. Salini • The 

 structure and affinities of Acmopyle pancheri, "pil^er 

 Acmopyle, a monotypic New Caledonian Podocarp, is 

 the most specialised member of the Podocarpinese 

 and closely allied to the genus Podocarpus, which it 

 resembles in the vegetative anatomy, drupaceous seed 

 megaspore membrane, young embryo, structure of 

 ma e cone, microsporophyll, pollen-grain, and probablv 

 male gametophyte. It differs from Podocarpus in (i) 

 the nearly erect seed; (2) the complete fusion of the 

 epimatium to the integument, even in the region of 

 the rnicropyle, in the formation of which it takes part • 

 and (3) the much greater development of the vascular 

 system of the seed, which forms a nearly continuous 

 cup-hke tracheal investment covering the basal two- 

 thirds of the stone, (a) The Taxineae are structurally 

 so distinct from the remaining conifers as to justify 

 their being placed in a separate phvlum, Taxales, 

 equivalent in rank, and related to, the Ginkgoales and 

 the Coniferales as here defined. The Cordaitalean 

 affinities of the Taxales are emphasised, (b) Con- 

 cerning the ovuliferous scale of the conifers, the con- 

 clusion is in favour of the brachyblast theory, support 

 for this view being derived froni the structure of the 

 megastrobilus of Acmopyle. (c) No definite opinion is 

 expressed on the question whether the conifers arose 

 ultimately from microphvllous or megaphyllous an- 

 cestors, for the origin of the Cordaitales themselves 

 is still regarded as sub jiidice. 



Zoological Society, April 27.— Dr. A. Smith Wood- 

 ward, vice-president, in the chair.— F. F. Laidlaw : 

 Contributions to a study of the dragon-fly fauna of 

 NO. 2637, VOL. 105] 



! Borneo. Part iv. : A list of the species known to 

 occur in the island.— Dr. R. Broom : Some new Therou 

 cephalian reptiles from the Karroo beds of South 

 Atrica. 



Manchester. 

 Literary and Philosophical Society, March 16.— Mr. 

 William Thomson, vice-president, in the chair.— Prof! 

 R. Robinson : Note on the mechanism of the produc- 

 tion of kynurenic acid in the dog. The formation of 

 kynuremc acid from tryptophane is susceptible of a 

 very simple representation involving normal reactions. 

 The process appears to be primarily one of oxidation 

 followed by decomposition of a carbamic acid deriva- 

 tive, and a probably spontaneous closing of the quino- 

 line ring.— Prof. A. Lapworth : Latent polarities of 

 atoms and mechanism of reaction, with special refer- 

 ence to carbonyl compounds. A consideration of the 

 properties of carbonyl compounds shows that divalent 

 oxygen and tervalent nitrogen tend to cause a latent 

 polarisation in the molecules of carbon compounds. 

 When this occurs in a molecule, the other atoms in 

 the neighbourhood show induced latent polarities 

 which the writer indicates by attaching - and + 

 signs to the atoms in alternating order, beginning 

 with the "key atoms," arriving at schemes like those 

 adopted by Fry and others. The induced polarity of 

 an atom or group is not interpreted as "necessarily 

 signifying an electric charge, but only as an en- 

 hanced or diminished tendency to attract or repel 

 other atoms (or electrons) with definite polar character, 

 and that only at the moment of chemical change (or 

 ionisation, when this occurs). A condition which 

 appears necessary for the full extension of the induc- 

 tive effect is the occurrence of double bonds (conjuga- 

 tion?), though it may survive the intervention of two 

 successive single ones. While divalent oxygen and 

 tervalent nitrogen (and especially the forrtier) seem 

 more effective than any other atoms, it would appear 

 that halogen (-), hydrogen ( + ), and metals ( + ) can 

 act as "key atoms" to a smaller extent; carbon 

 appears almost indifferent. This principle includes 

 Markownikoff's rule of addition, the rules of substitu- 

 tion in the benzene series, the rules of reaction of 

 saturated and unsaturated ketones, nitriles, and carb- 

 oxylic acids, as well as of their halogen derivatives. 

 The influence of hydrogen as a "key atom" is per- 

 ceptible in the cresols, of which the relative acidities 

 can be foreseen from a consideration of the influence 

 of the hydrogen atom in the methyl groups on the 

 latent polarities of the atoms > in hydroxyl groups. — 

 Prof. R. Robinson : The conjugation of partial valen- 

 cies. The author deals with the mechanism of chemical 

 processes on the basis of a hypothesis of divisible 

 valency, assuming that activation of molecules is due 

 to a partial dissociation or splitting of valencies, and 

 that only molecules so polarised take part in re- 

 actions. This accounts for the well-recognised effect 

 of polar atoms on alternate atoms in a chain, and 

 the theory is extended to include cases such as the 

 addition of hydrogen bromide to allyl bromide, where 

 the coniugation of ethylene linkaere and bromine atom 

 is relatively weak. Conjugated decompositions and 

 the problem of molecular rearrangement are dealt with. 



P.'iRIS. 



Academy of Sciences, April 19.— M. Henri Deslandres 

 in the chair. — G. A. Boulenger : The fossil Gavialis of 

 Omo. — A. VayssiJre : The marine fauna of the western 

 coast of the Gulf of Marseilles.— G. Julia : New pro- 

 perties of certain very general classes of integral or 

 meromorphic functions.- — W. Sierpinski : Functions of 

 the first class.— Fr. Lange-Nielsen : A generalisation 

 of Rolle's theorem.— J. Villey : Flight at high alti- 



