[42 



NATURE 



[June i i, 1903 



that the known larvae of the British Crangonidae fell 

 naturally into three groups, representing the genera /Egeon 

 (which would include Cheraphilus), Crangon, and Ponto- 

 philus. — Mr. C. Tate Regra^n read a paper on the fishes 

 collected by Dr. Goeldi at Rio Janeiro. Four species were 

 described as new. — Mr. Martin Jacoby described fifty-six 

 new species of South American Coleoptera of the family 

 Chrysomelidae. 



Geological Society, May 13.— Mr, E. T. Newton, F.R.S., 

 vice-president, in the chair. — On some disturbances in the 

 Chalk near Royston (Hertfordshire), by Mr. H. B. Wood- 

 ward, F.R.S. The disturbed Chalk near Royston, with 

 its fractured and displaced flints, occurs in conjunction with 

 Boulder-clay, and the latter is found beneath a considerable 

 thickness of disturbed Chalk. While Boulder-clay occurs 

 along the high ground bounding the disturbed area to the 

 south, the undulating downs to the north are devoid of this 

 Glacial Drift. The facts were to be explained, on the 

 land-ice theory, if the ice were at first welded to the rubbly 

 surface-strata in regions north of the escarpment, and, when 

 movement set in, there were overthrusts of debris-laden 

 ice, and upper layers of ice were rent asunder from and 

 moved over lower ones ; while to the thrust or long-con- 

 tinued pressure of ice along shear-planes at the higher 

 levels may be attributed the belt of disturbed strata. — On 

 a section at Cowley, near Cheltenham, and its bearing 

 upon the interpretation of the Bajocian denudation, by Mr. 

 L. Richardson. — Description of a species of Heterastraea 

 from the Lower Rhaetic of Gloucestershire, by Mr. R. F. 

 Tomes. The specimen was obtained from Lower Rhaetic 

 Beds at Deer.hurst (Gloucester). It occurred a little above 

 the bone-bed ; it is. specifically new and generically new to 

 the Rhaetic, and it displays Jurassic relationships! It 

 differs from the several Liassic species in the small size of 

 the corallum and of its calices. 



Royal Meteorological Society, May 20. — Captain D 

 Wilson-Barker, president, in the chair. — Mr. C. P. Hooker 

 read a paper on the relation of the rainfall to the depth of 

 water in a well. In this he gave the weekly measurements 

 of the depth of water in a well (loi feet deep) and the 

 amount of rainfall at Cirencester, extending over the sixteen 

 years 1887-1902. The depth of water in the well depends 

 on how much rain penetrates, and the penetration is deter- 

 mined by the amount of rain, the rapidity of its fall, and 

 the existing condition of the soil. The winter rains pene- 

 trate easily, and the summer rains with difficulty. Mere 

 absence of rain is not the only cause of scarcity, deficiency 

 of spring rains, and subsequent heat and evaporation being 

 far more important factors. After the early spring months 

 but little rain penetrates to the well, so that a timely fore- 

 warning, at that season might prove of great value by en- 

 abling the existing supplies to be husbanded at an early 

 period. Considering how narrow is the boundary between 

 sufficiency and want, and looking to the fact that every 

 year sees further demands made on our water supplies, the 

 author considers that it is of the utmost importance that 

 more attention should be paid to the storage of our surplus 

 winter rains. This -might be done by the formation of 

 large hill reservoirs, and doubtless such measures as the 

 reafforesting of large tracts of land would be of use in 

 checking the rapidity with which the rains reach the rivers 

 and are so lost. — Mr. W. Marriott gave an account of the 

 frost of April, which was so keenly felt coming after 

 the long spell of very mild weather in "February and March. 

 The fortnight April 12-25 was marked by keen northerly 

 winds, great dryness, and low temperatures. Frosts on 

 nhe ground were of almost nightly occurrence, and as the 

 result, the destruction of the fruit blossom has been verv 

 great and also very general. In many places a good deal 

 of the apple and strawberry blossom, although only in bud 

 at the time, was killed, while, potatoes were cut to the 

 ground, and the foliage of horse chestnuts and limes much 

 injured, particularly on the windward side. 



Royal Microscopical Society, May 20.— Dr. Hy. Wood- 

 ward, F.R.S. , in the chair.— Mr. C. L. Curties exhibited 

 a new monochromatic light apparatus, which was a modi- 

 fication of that shown at the November meeting by Dr. 

 Spitta. It consisted of an optical bench carrying a Nernst 

 electric lamp, aplanatic bulls-eye condenser, adjustable slit, 

 achromatic collimating lens, a prism upon which was 

 WO. 1754, VOL. 68J 



mounted a Thorpe replica grating, and an achromatic 

 projection lens, the whole being fitted upon a mahogany 

 base capable of being tilted. The spectrum given was ex- 

 ceedingly brilliant, and any part could be brought into the 

 field of the microscope. — Messrs. W. Watson and Sons 

 exhibited a new form of museum microscope placed inside 

 a locked glass case through which the eye-piece projected. 

 There was a circular disc in place of the ordinary stage, 

 upon which twelve slides could be fixed ; it was rotated 

 from the outside, so as to bring each object into the field. 

 Messrs. Watson also exhibited a bulls-eye condenser of 

 long focus for photomicrographic purposes, fitted with iris 

 diaphragm and centring adjustments.— There was an ex- 

 hibition of pond life by fellows of the Society and members 

 of the Quekett Microscopical Club. — It was announced that 

 at the next meeting on June 17 there would be a communi- 

 cation from Lord Rayleigh on Mr. Gordon's paper on the 

 Helmholtz theory of the microscope, and that Dr. H. 

 Siedentopf would give a demonstration of his method of 

 making visible ultra-microscopic particles in glass, and the 

 application of the method to bacteria. 

 Cambridge. 

 Philosophical Society, May 4. — Dr. Baker, president, 

 in the chair. — On Mendelian heredity of three characters 

 allelomorphic to each other, by Mr. W. Bateson, F.R.S. 

 The object of this note was to direct attention to various 

 possibilities attainable by a modification of the Mendelian 

 method. In the ordinary method the constitution of the 

 gametes in the first cross (F,) is tested by breeding such 

 individuals inter se or with a pure recessive. The ensuing 

 generation (Fj) will consist of a mixture of dominant and 

 recessive individuals ; but if the proportions depart from 

 the expected 3 : i or i : i, it is not possible to tell whether 

 such departure is due to change in relative numbers of 

 dominant and recessive gametes, to imperfect segregation 

 of characters, or to change in dominance. This question 

 can in part be answered by a method which consists m cross- 

 ing F, produced from a parent having one dominant 

 character with another heterozygous individual having a 

 different dominant character (the same recessive being used 

 in both cases). — On the diathermancy of antimonite, by Mr. 

 A. Hutchinson. — On the potential difference between the 

 terminals of a vacuum tube, by Mr. W. A. D. nudgo. 

 The experiments described in the paper were made in a 

 tube which contained a perforated and movable metal 

 disc. It was found that the presence of the disc caused 

 the potential difference between the ends of the tube to rise 

 considerably above that of a perfectly similar tube without 

 a disc. The increase varied with the nature of the metal ; 

 using different metals as discs, the order of increase was 

 Pb I, Ag 1-25, (Cu Fe Zn) 135, Al 35, Mg 38.- The deter- 

 mination of curves satisfying given conditions, by Mr. H. 

 Bateman. — On the existence of a radio-active gas in the 

 Cambridge tap-water, by Prof. Thomson, F.R.S. (see p. 90). 

 — On a continuous spectrum, by Mr. T. H. Havelock. — On 

 the Thomson effect in alloys of bismuth and tin, by Mr. S. C 

 Laws. The quantity of heat evolved or absorbed in con- 

 sequence of the temperature gradient when a current C 

 passes between two sections of a homogeneous conductor the 

 difference of temperature of which is 5T may be represented 

 by CffST. These experiments comprise some measurements 

 of the quantity o-— the specific heat of electricity — in bis- 

 muth and alloys of bismuth and tin. Some values for <r 

 obtained in this way are : — bismuth 860 ergs per absolute 

 unit current per 1° C. ; alloy containing 13 per cent, tin 

 10,700 ergs per absolute unit current per 1° C. ; alloy con- 

 taining 6 per cent, tin 11,200 ergs per absolute unit current 

 per 1° C. — A preliminary account of an investigation of 

 the effect of temperature on the ionisation of gases acted 

 on by Rontgen rays, by Mr. R. K. McClung:. This paper 

 gives some of the results obtained in a series of experi- 

 ments made to ascertain what effect the heating of a gas 

 has on the amount of ionisation produced in it by the action 

 of Rontgen rays. The results obtained show conclusively 

 that the amount of ionisation is independent of the tempera- 

 ture of the gas when the density of the gas is kept constant. 

 Observations were made on air for a range of temperatures 

 of nearly two hundred degrees from about 9° C. to a little 

 more than 200° C. Carbon dioxide was also examined for 

 a slightly wider range of temperatures, and precisely the 

 same result was obtained as for air. 



