March 17, 1921] 



NATURE 



93 



structure of their tests ; the structure of Saccam- 

 mina is not inconsistent with that of the arenaceous 

 Foraminifera, and thus one is led to assign this fossil 

 to the group originally proposed for it by Brady. — 

 Dr. T. S. Wilson : Notes on the views of the late Prof, 

 Charles Lapworth with regard to spiral movements 

 in rocks during elevation or depression. During Prof. 

 Lapworth 's only visit to Wengen Alp, near Lauter- 

 brunnen, he was able to infer the presence of rock- 

 circles (due to spiral movements) some hundreds of 

 , feet up the hillside. Prof. Lapworth 's theory of 

 wave-movement is applied to solids, and the type of 

 deformation which a cube would undergo if acted 

 upon by wave-crests and wave-troughs from three 

 different directions is discussed. By this method of 

 investigation it is possible to demonstrate the condi- 

 tions under which shearing would take place in the 

 centre of the cube, along the main septal line between 

 the positive and the negative portion of the fold. 



Association of Economic Biologists, March ii. — Sir 

 David Prain in the chair. — Dr. J. Davidson : The cells 

 of plant tissues in relation to cell-sap as the food of 

 Aphids. After describing the sucking apparatus of 

 Aphids, the relation of the stylet to the plant 

 tissues was considered, particular regard being paid 

 to the course of the puncture, the effect upon the cell 

 contents, the tissues affected, and the food value of 

 saps at different ages of the plant. The very interesting 

 relation between the size of Aphids upon various food- 

 plants was discussed in the light of the difficulties 

 that this introduces in specific determinations. — E. R. 

 Speyer : Ceylon Ambrosia beetles and their relation to 

 problems of plant physiology. Of the sixty-six 

 Scolytid beetles in Ceylon associated with Ambrosia 

 t fungi, thirty-two belong to the genus Xyleborus. The 

 bionomics of these beetles was briefly described, and 

 aji account given, illustrated by very fine specimens, 

 of the tunnelling they make in their host trees. The 

 pure cultures of degenerate Ascomycetous fungi main- 

 tained by the insects in their tunnels were described, 

 each species of beetle having its own particular fungus, 

 and a number of hypotheses were advanced to explain 

 them. The paper closed with a brief review of the 

 various insect groups which are known to cultivate 

 fungi and of the organisms maintained. 



Edinburgh. 



Royal Society, March 7.— Prof. F. O. Bower, presi- 

 dent, in the chair. — Prof. A. R. Home : A graphical 

 rnethod of determining shear influence lines and 

 diagrams of maximum shearing force for a beam sub- 

 jected to a series of concentrated rolling loads. The 

 paper describes a graphical method of constructing 

 shear influence lines. These lines are of importance 

 to civil engineers in connection with the design of 

 railway bridees and other structures which are sub- 

 jected_ to rolling loads. They are of special import- 

 ance in structures of reinforced concrete. Up to the 

 present it has been the practice to determine these 

 influence lines by calculation, which process becomes 

 very laborious when the number of loads is consider- 

 able, as, for example, in the case of the wheel loads 

 of a locomotive. The method is extended to make 

 possible the determination of the maximum shearing 

 force which occurs at each section in the length of 

 the bridge or structure without any calculation being 

 necessarv.— Dr. J. M'L. Thompson : Studies in floral 

 morphology. No. 2 : The staminal zvgomorphv of 

 Couroupita gutanensis, Aubl. In this communication 

 the development of the remarkable lopsidedness of the 

 flowers of Couroupita (the cannon-ball tree) is 

 described. A general description of the tree itself 

 NO. 2681, VOL. 107] 



is provided from the author's observations in Jamaica, 

 and the crowded inflorescences and massive spherical 

 fruits are illustrated. It is shown that the most con- 

 spicuous floral features of Couroupita are due to the 

 separation of the male organs into two portions 

 during development. The first is a fleshy ring round 

 the style and bearing numerous short stamens, all of 

 which produce small pollen-grains. The second is a 

 long, strap-shaped, fleshy structure which is borne on 

 the outer side of the flower. It ends in a massive 

 ovoid body hanging over the centre of the flower, and 

 carries long, fleshy stamens which produce large 

 pollen-grains. It is this large, fleshy body which is 

 the chief cause of the lopsidedness of the flowers. In 

 the course of its development it assumes remarkable 

 features. At an early stage its component cells 

 become very large compared with those of the remain- 

 ing male organs. A cellular gigantism is thus begun 

 which is maintained throughout its entire history. It 

 is to this cellular gigantism and to the active growth 

 which accompanies it that the lopsidedness or zygo- 

 morphy of the stamens is due. The communication 

 was illustrated by photographs and drawings showing 

 the habit of the cannon-ball tree and the structure 

 of its flowers and fruits, and formed the preface to a 

 general study of the floral characters of the genera 

 with which Couroupita is allied. 



Paris. 



Academy of Sciences, February 21. — M. Georges 

 Lemoine in the chair.— H. Deslandres and V. Burson : 

 Researches on the atmosphere of stars. The recogni- 

 tion of stars which show the same bright lines as are. 

 observed in the sun. As the result of a search for 

 bright chromospheric lines in stars, particularly in 

 stars of the F, G, and K types, the Kj and Hj lines 

 have been detected in eight stars and the K2 line 

 alone in two others, and a list of these stars is given. 

 Only one of these, a Auriga, is of the solar G type. — 

 P. Termier and L. Joleaud : The overlapping frag- 

 ments of Propiac (Dr6me), evidence of a great sheet 

 of alpine origin, pushed, laefore the Miocene, on to 

 the valley) of the Rh6ne.— F. Widal and P. Vallery- 

 Radot : Desensibilisation and resensibilisation at will 

 in a patient anaphylactised to antipyrine. — G. Gouy : 

 Aplanetism and the law of sines. — C. Guichard : 

 Certain networks which occur in the study of the 

 congruences belonging to a linear complex, — M. de 

 Sparre : Calculation of the ram stroke in a pipe 

 supplying a turbine with strong reaction, — P. 

 Vnillemin : Endogenous zygomorphosis in flowers 

 normally actipomorphs. — Sir Ernest Rutherford was 

 elected a correspondant of the Academy for the sec- 

 tion of general physics in succession to A. Michelson, 

 elected foreign associate, and Jules Bordet corre- 

 spondant for the section of medicine and surgery in 

 succession to the late Pierre Morat. — R. Wavre : An 

 equation of Fredholm in the complex domain and its 

 application to the theory of systems of linear equa- 

 tions with an infinity of unknowns. — B. Delaunay : 

 The solution of the indeterminate equation 



qX'-pX'Y+nXY'+Y'=u 



— G. BOuligand : Certain modes of determination of 

 the solutions of Ati = (x>'u. — M. Holweck : The ab- 

 sorption of X-rays of great wave-length. Connection 

 between the X-rays and light.— G. Claude : The syn- 

 thesis of ammonia under very high pressure : the 

 present state of the experiments. In January, iq2o, 

 several members of the Academy saw the first work- 

 ing plant outside the laboratory ; it produced 6 to 

 7 litres of liquid ammonia per hour. After various 

 changes in the catalysers, at a second visit on Novem- 



