i6o 



NATURE 



[December i, 1910 



exposed, namely, shales, small coal-seams, sandstones, and 

 a ferruginous bed. The beds are of Lower Oolite age, 

 and belong to the Lower Estuarine series. From this 

 quarry Dictyozamites was recorded for the first time in 

 England. The writer has obtained nearly forty species 

 from the quarry, among which are many characteristic 

 Wealden plants. 



Physical Society, November ii. — Prof. H. L. Callendar, 

 F.R.S., president, in the chair. — Dr. C. Chree : The 

 supposed propagation of equatorial magnetic disturbances 

 with velocities of the order of loo miles per second. The 

 question of the simultaneity of magnetic disturbances re- 

 corded at different stations has recently been discussed by 

 Dr. Bauer and Mr. Paris. A good many magnetic storms 

 have so-called " sudden commencements." As regards 

 these " sudden " changes, three things are conceivable : 

 they may be absolutely simultaneous at different stations ; 

 there may be a very small difference of time corresponding 

 to the rate of propagation of electromagnetic waves ; or, 

 finally, there may be, as Dr. Bauer concludes, longer 

 intervals, amounting to several minutes, for stations re- 

 mote from one another. Dr. Bauer concludes that Mr. 

 Faris's figures demonstrate the truth of his theory that 

 disturbances normally are propagated round the earth, 

 sometimes eastwards, sometimes westward, the time of a 

 complete revolution averaging about 3I minutes. The 

 author of the present paper discusses the weaknesses of 

 Dr. Bauer's theory. He points out that the theory could 

 be adequately tested by a careful comparison of curves 

 from selected stations fairly encircling the globe, choosing, 

 if possible, stations the time-measurements of which are 

 specially trustworthy. — Prof. W. B. Morton : Cusped 

 waves of light and the theory of the rainbow. Diagrams 

 were shown of the forms assumed by a plane wave of 

 light falling on a spherical raindrop and twice reflected 

 from the interior of the drop, as well as the waves emerg- 

 ing from the drop. The waves in general have cuspidal 

 edges, which run along the caustic surfaces. This rela- 

 tion between the caustic and the cusps on the waves was 

 pointed out by Wood in connection with the similar waves 

 produced by reflection at a spherical surface. It had been 

 noticed earlier by Pol'ter, Jamin, and Mac^ de Lepinay. 

 The phase over a wave of this type is not constant, the 

 two portions on opposite sides of a cusp differing in 

 general by a quarter period. Attention was directed to 

 the advantage of regarding the distribution of light in the 

 rainbow as the consequence of the interference of the 

 cusped waves which run down to the observer's eye along 

 the direction of minimum deviation. This way of looking 

 at the matter is shown to be equivalent to Mascart's 

 approximate method of explanation of the formation of the 

 supernumerary bows by interference of disturbances 

 coming from the two poles on the special wave-form used 

 by Airy. 



Zoological Society, November 15. — Dr. S. F. Harmer, 

 F.R.S., vice-president, in the chair. — J. Lewis Bonhote : 

 Experiments on the occurrence of the web-foot character 

 in pigeons. After referring to Mr. R. Staples Browne's 

 paper on the subject in the Proc. Zool. Soc. for 1905, in 

 which the web-foot was shown to be a simple Mendelian 

 recessive, Mr. Bonhote instanced further cases from the 

 lofts of Mr. F. W. Smalley that bore out Mr. Staples 

 Browne's conclusions. Both these gentlemen, however, 

 gave the author birds from their strains, and in the first 

 instance when webbed birds from the different strains 

 were crossed an irregular result — namely, four normal and 

 one webbed — was obtained. Matings from these birds 

 were continued, and the results were, in almost every 

 case, contrary to Mendelian expectations, normals throw- 

 ing webs and webs throwing normals. After discussing 

 various suggestions, Mr. Bonhote came to the conclusion 

 that no really satisfactory explanation was forthcoming. 

 The Mendelian inheritance was apparently there, but 

 dominated and modified by some other agency. — E. 

 Degren : Notes on the little known lizard Lacerta jacksoni, 

 Blgr., with special reference to its cranial characters. — 

 G. A. Boulengrer : Lacerta peloponnesiaca, Bibr. A new 

 description of this little known lizard, made from living 



NO. 2144, VOL. 85] 



specimens in the society's gardens, with the view of fixing 

 its correct position in the genus Lacerta. — E. G. 

 Boulengrer : Remarks on two species of fishes of the 

 genus Gobius, from observations made at Roscoff. The 

 paper dealt with the specific distinction of Gobius minulus 

 and G. microps. 



Linnean Society, November 17. — Dr. D. H. Scott, F.R.S.» 

 president, in the chair. — Prof. G. Henslow : A theoretical 

 origin of Plantago maritima, L., and P. alpina, L., from 

 P. Coronopus, L. Vars. This suggestion arose from the 

 presence of P. maritima around the erection of faggots for 

 condensing the brine of the salt-spring of Bad Nauheim, 

 which is some 240 miles from the nearest coast, for M. 

 Lesage proved that fleshiness of maritime plants was the 

 direct result of the presence of salt. P. Coronopus has 

 many varieties, and all the characters upon which they 

 are based are very variable ; forms approximating the 

 above species are already named. — Prof. G. Henslow : 

 A theoretical origin of Monocotyledons from aquatic 

 Dicotyledons through self-adaptation to an aquatic habit, 

 being supplementary observations to a previous paper 

 (Journ. Linn. Soc, Bot. xxix.. [1892], p. 485). The con- 

 clusions arrived at are : — (i) Coincidences are innumerable 

 in all parts of monocotyledonous plants with aquatic 

 Dicotyledons. (2) Experimental verification now covers 

 and explains a large proportion of these coincidences. 

 (3) Terrestrial Monocotyledons retain by heredity many of 

 the aquatic characters acquired by their ancestors when 

 living a hydrophytic life, but they are now readapted to 

 a life in air. 



Melbourne. 



Royal Society of Victoria, October. — Prof. E. W. Skeats 

 in the chair. — ^T. S. Hall : The systematic position of the 

 species of Squalodon and Zeuglodon described from 

 Australia and New Zealand. Squalodon ivilkinsoni, 

 McCoy, Zeuglodon harwoodi, Sanger, Kekenodon 

 onamata, Hector ; and Prosqualodon australis, Lydekker. 

 agree in having the molar roots fused, as distinct from 

 the northern hemisphere forms. New genera based on the 

 proportion of crown to fang are proposed, namely, Para- 

 squalodon (ivilkinsoni) and Metasqualodon (harwoodi). — 

 C. M. Maplestone : Further descriptions of the Tertiary 

 polyzoa of Victoria, part xi. A new family, Synapti- 

 cellidae, with n.g. Synapticella (6 spp.), is founded. The 

 family is allied to Catenicellidae and Eucratidae, but the 

 zoaria are free and rigid, and the zocecia in single series. 

 In all, 38 new species are described. — F. Chapman : A 

 trilobite fauna of Upper Cambrian age (Olenus series) in 

 N.E. Gippsland, Victoria. E. O. Thiele found a lime- 

 stone near Mt. Wellington which he, Skeats, and Dunn 

 hold to be interbedded in slates which on graptolite 

 evidence are Upper Ordovician. The author records 

 Agnostus, Crepicephalus, and Ptychoparia, besides brachio- 

 pods and a few other forms, all of which are held to show 

 Cambrian affinities. — A. J. Ewart, Jean White, and 

 Bertha Wood : Contributions to the flora of Australia, 

 No. 16. The authors described a new grass, Sarga. n.g., 

 from N.W. Australia, a new Linum from Tasmania, and 

 others. 



Cambridge. 



Philosophical Society, November 14. — Prof. Wood in the 

 chair. — Prof. BifTen : Some crosses with Rivet wheat. 

 Cases of coupling of roughness of the chaff with grey 

 colour were described from several crosses between sub- 

 s{>ecies of Triticum sativum, and also a case where two 

 varieties normally immune to the attacks of Claviceps 

 purpurea gave rise to an F^ generation containing 

 susceptible individuals. — Mrs. D. Thoday and D. 

 Thoday : The inheritance of the yellow tinge in sweet- 

 pea colouring. The yellow tinge in scarlet, salmon, and 

 deep cream sweet peas is found to be very complex in 

 character. In the deepest tinged flowers examined, Queen 

 Alexandra and St. George, the yellow colouring is pro- 

 duced by at least three coincident recessive factors. The 

 three are all independent of one another ; two tinge_ the 

 sap and affect the whole flower, while the third is a 

 plastid character, especially affecting the standard and pro- 



