i86 



NATURE 



[April S, 1920 



the school buildings having been kindly lent by the 

 governors for this purpose. The object of the 

 Summer School is to provide theoretical and practical 

 instruction in the methods of geography and to furnish 

 opportunities for the discussion and elucidation of 

 problems connected with the teaching of the subject. 

 The course will consist of lectures, laboratory work, 

 field work, and demonstrations. Lectures will begin 

 on Morning morning, August 2, and the course will 

 end on Saturday, August 21. Among the lecturers 

 will be Prof. Kendall (professor of geology in the 

 University of Leeds), Dr. A. Gilligan (lecturer in 

 economic geology), Mr. C. B. Fawcett (lecturer in 

 geography), Dr. W. G. Smith (lecturer in agricultural 

 botany at the Edinburgh and East of Scotland Insti- 

 tute), and Mr. W. P. Welpton (lecturer in education 

 and master of method in the University of Leeds). 

 Applications for tickets should be made to the Secre- 

 tary of the Yorkshire Summer School of Geography, 

 The University, Leeds. 



Bedford College for Women, a constituent college 

 of the University of London, and the largest and 

 oldest university college for women in England, has 

 issued an appeal for funds. At the moment, when 

 there is an overwhelming demand by women for 

 higher education and training, the college must either 

 refuse admission to highly suitable students and 

 starve or close down certain departments, or it must 

 enlarge its buildings and increase its endowments. 

 Seven hundred students now crowd into buildings 

 adapted for four hundred and fifty, with the result that 

 in many cases classes have to be triplicated and class- 

 rooms and apparatus shared between different depart- 

 ments. A sum of ioo,oooZ. is needed for additional 

 lecture-rooms and laboratories. A second ioo,oooZ. is 

 required for endowment, notably for scholarships, the 

 various departments of science, the department of 

 social studies, and the training department. A third 

 100,000?. is badly needed for a hostel. An opportunity 

 for acquiring an admirable site just outside Regent's 

 Park has presented itself. Whether the college can 

 take advantage of this must depend on the generosity 

 of the public. It should, perhaps, be emphasised that, 

 apart from such developments, the income of the col- 

 lege is by no means sufficient for its present needs 

 in view of the enormously increased cost of mainten- 

 ance and the necessity for raising all salaries. The 

 work of universities in the past could never have been 

 done had there not lived generous men and women 

 who believed thev could render no greater public ser- 

 vice than by endowing colleges and thus furnishing 

 opportunities for rich and poor to acquire sound 

 learning. May we hope that a like generosity and a 

 like belief exists to-day? The Queen's interest in the 

 college is well known, and has taken the practical 

 form of giving a donation. Subscriptions should be 

 sent to Viscountess Elveden, hon. treasurer of the 

 Bedford College Endowment and Extension Fund, 

 Bedford College, Regent's Park, N.W.i. 



Societies and Academies. 



London. 



Royal Society, March 18.— Sir J. J. Thomson, presi- 

 dent, in the chair.— W. B. Brierley : A form of Botrytis 

 cinerea with colourless sclerotia. A form of Botrytis 

 cinerea with colourless sclerotia Is described. This 

 was obtained by the isolation and growth of a colour- 

 less sclerotium, which was formed in a culture of a 

 normal strain derived from a single spore. The 

 primary origin of the change resulting in the albino 

 form is located in the hyphal mother-cell from which 



NO. 2632, VOL. 105] 



the initial colourless sclerotium arose. Lotsy's dictum 

 that "certainty of purity is a conditio sine qua non 

 to obtain proof of the existence of mutation in living 

 beings" is accepted, and it is shown that such a state 

 is possibly not realisable in the fungi. It is suggested 

 that somatic fusions resulting in a change of genotvpic 

 values are the mechanism whereby evolution in the 

 fungi has taken place. — R. R. Gates : A preliminary 

 account of the meiotic phenomena in the pollen 

 mother-cells and tapetum of lettuce (Lactuca sativa). 

 In a preliminary study of meiosis in the pollen 

 development of lettuce, several points have appeared 

 which have a general bearing on cytological concep- 

 tions and the problems of genetics. The exceptional 

 condition has been found in lettuce, in which every 

 intergrade occurs between pollen mother-cells and 

 tapetal cells. Even synapsis has been observed in 

 binucleate tapetal cells, which emphasises the physio- 

 logical aspects of the synaptic contraction. 'The 

 tapetal cells are peculiar in being often very much 

 elongated and lying lengthwise of the 'anther. 

 Ultimately they break down and form a plasmodium 

 surrounding the pollen-grains. Cytomvxis also 

 occurs, though rarely, during the stage of synapsis 

 in the pollen mother-cells. 



March 25.— Sir J. J. Thomson, president, in the 

 chair.— A. R. Forsyth : Note on the central differential 

 equation in the relativity theory of gravitation. The 

 critical equation in Prof. Einstein's theory is — 



so that i^J^ = 277t (u - a) {11 -^){u- y), 



where a, /S, y are proved to be real and positive for 

 the known planetary bodies in the solar system, and 

 are arranged so that a>P>y. 



There is no need for initial approximation. The 

 equation can be integrated exactly, in terms of elliptic 

 functions. The integral is — 



^)/p} 

 i+dtt {{<p-m)lp\ 

 where (^ = ct at perihelion; the modulus of the elliptic 

 functions is given by — 



P—P — 7 and p = {2m (a — y)}~i 

 a-y 



Further, the advance of the perihelion in one revolu- 

 tion is — 



4pK— 2n-, 

 where K is the complete first elliptic integral with the 

 modulus fe. These expressions are accurate (and not 

 approximate) in relation to the initial equation. For 

 approximations in connection with the known members 

 of the solar system, k^ is small, so that K is slightly 

 greater than \tt, and p is slightly greater than unity. 

 The advance of the perihelion is 2n-.3m^/A^; and the 

 value of u is — 



^'2 { I -}- ^ cos ((/) - ci) + ^ ^2 sin2 (0 - trr) 



-y+(^-v)^t^?4^ 



+ 3p^(^- 



j) sin (0- 



— R. D. Oldham: The frequency of earthquakes in 

 Italy in the years 1896 to 1914. The paper is an 

 attempt to discover whether there is any variation in 

 the frequency of earthquakes which can be attributed 

 to the stresses set up by the gravitational attraction 

 of the sun and the moon. In addition to some small 

 and more or less doubtful variations, there was found 

 to be a very marked maximum frequency about the 

 time of the new moon, when the declinations of the 

 sun and moon were of the same sign and at the full 



