February 4, 191 5] 



NATURE 



635 



.Wertheimer writes to say that the system has pre- 

 vailed for many years, and that it has resulted in a 

 great increase of efficiency and in an improved prestige 

 of the college in the eyes of the heads of the firms 

 which employ students who have gone through their 

 engineering training at Bristol. 



The King has appointed a new Royal Commission 

 for the following purposes : — To inquire into and 

 report on the methods of making appointments to 

 and promotions in the Civil Service, including the 

 Diplomatic and Consular Services, and the legal 

 departments ; to investigate the working and effici- 

 ency of the system of competitive examination for 

 such appointments, and to make recommendations 

 for any alterations or improvements in that system 

 which may appear to be advisable; and to consider 

 whether the existing scheme of organisation meets 

 the requirements of the Public Service, and to suggest 

 any modifications which may be needed therein. The 

 members of the Commission are as follows :— Sir 

 H. B. Smith (chairman), Duke of Devonshire, 

 Bishop of Southwark, Sir J. P. Hewett, Sir Donald 

 Macalister, Sir J. A. Kempe, Mr. S. J. G. Hoare, 

 Mr. A. C. T. Beck, Mr. A. A. Booth, Mr. A. Bout- 

 wood, Mr. J. R. Clvnes, Mr. C. Coward, Mr. R. D. 

 Holt, Mr. P. E. Matheson, Dr. A. E. Shipley, Mr. 

 P. Snowden, Mr. Graham Wallas, Miss E. S. 

 Haldane, and Mrs. L. A. E. Streatfeild. 



SOCIETIES AND ACADEMIES. 

 London. 

 Royal Society, January 28.— Sir William Crooks, 

 president, in the chair. — W. W. C. Topley : The influ- 

 ence of salt-concentration on haemolysis. The method 

 employed in this investigation has consisted in var\- 

 ing the percentage of sodium chloride present in a 

 mixture of sheep's red cells, haemolytic anti-body and 

 complement. The haemolytic anti-body was obtained 

 from an immunised rabbit, and fresh guinea-pig 

 serum, previously absorbed with sheep's red cells at 

 0° C, furnished the complement. Where hypotonic 

 percentages of sodium chloride have been employed, 

 the solutions have been made in 78 per cent, sac- 

 charose solution. The results have confirmed the ob- 

 servations of other workers that, when the percentage 

 of salt is increased beyond the normal limit, haemolysis 

 is inhibited, owing to the failure of union between 

 the complement and the red-cell anti-body complex, 

 and that, if the amount of anti-body present in the 

 mixture be increased, the effect of the increased salt 

 concentration may to a certain extent be overcome. 

 It has further been shown that, if the salt concen- 

 tration be decreased below the normal limits, less and 

 less anti-body becomes necessary in order to bring 

 about the union of red cells and complement, and that, 

 in the almost entire absence of electrolytes, guinea- 

 pigs' complement can haemolyse sheep's red cells with- 

 out the intervention of haemolvtic anti-body. — G. 

 Smith : The life-cycle of Cladocera, with remarks on 

 the physiology of growth and reproduction in Crus- 

 tacea. As the result of breeding experiments, it is 

 shown that the effects of isolation, crowding, and 

 temperature are the same for Daphnia pulex as pre- 

 viously reported for Moina rectirostris, viz., isolation 

 combined with high temperature completely inhibits 

 the production of sexual individuals, reproduction 

 being entirely parthenogenetic. Crowding, combined 

 with low temperature, results sooner or later in the 

 production of males and ephippial females. — T. 

 Goodey : Investij^ations on proto2oa in relation to the 

 factor limiting bacterial activit\' in soil. Two different 



NO. 2362, VOL. 94I 



lots of soil were taken and inoculated with cultures 

 of protozoa originally obtained from soil, in order to 

 determine whether the added protozoa would cause a 

 decrease in the numbers of bacteria in the soil. One 

 soil was free from protozoa to begin with, having 

 been bottled since 1846, whilst the other was freed 

 from protozoa by partial sterilisation. Separate lots of 

 each soil were inoculated with cultures of ciliates, 

 amoebae, and flagellates, and suitable control samples 

 were set up. Periodical bacterial counts were made in 

 order to ascertain if the protozoa were exerting a 

 limiting action on the soil bacteria, and these counts 

 were continued over a period of about eighteen 

 months. The general conclusion drawn from the in- 

 vestigations is that ciliates, amoebae, and flagellates 

 do not act as the factor limiting bacterial activity in 

 soil. — S. Hatta : The mesodermic origin and fate of 

 the so-called mesectoderm in petromyzon. The name 

 mesectoderm has given to a loose aggregation of 

 mesenchymatous tissue, in some places assuming the 

 character of an epithelium intervening between the 

 myotomes and the ectoderm in the head and branchial 

 region of the embryo of petromyzon. As the name 

 implies, it has been confidently asserted that this 

 tissue is derived from the ectoderm. In this paper, 

 however, it is shown that this tissue originates from 

 the ventral edge of the myotome and corresponds to 

 the ventral extension of the myotome in the trunk 

 region which grows downwards towards the mid- 

 ventral line outside the splanchnocoele and gives rise 

 to the ventral muscles of the trunk. — Prof. J. C. Bose : 

 The influence of homodromous and heterodromous 

 electric currents on transmission of excitation in plant 

 and animal. The action of an electric current in in- 

 ducing variation of conductivity may be enunciated 

 under the following laws, which are equally applic- 

 able to the conducting tissue of the plant and the 

 ner\'e of the animal : — (i) The passage of a current 

 induces a variation of conductivity, the effect depend- 

 ing on the direction and intensity of current. (2) 

 Under feeble intensity, heterodromous current en- 

 hances and homodromous current depresses the con- 

 duction of excitation. (3) The after-effect of a feeble 

 current is a transient conductivity-variation, the sig^ 

 of which is opposite to that induced during the con- 

 tinuation of current. (4) The normal conductivity- 

 variation undergoes a reversal under a strength of cur- 

 rent above the critical value. The heterodromous cur- 

 rent then induces a depression while the homodromous 

 current induces an enhancement of conductivity. 



Geological Society, Januar)- 20. — Dr. A. Smith Wood- 

 ward, president, in the chair. — Prof. O. T. Jones and 

 W. J. Pngh : The geology of the district around 

 Machynlleth and the Llyfnant Valley. An account is 

 given of the physical features, general succession, and 

 structure of the area. The rocks are sharply folded, 

 and sometimes overfolded, towards the east. Their 

 axes range approximately north-north-east and south- 

 south-west; the folds in the central area pitch north- 

 wards, but north of the Dovey a southerly pitch sets 

 in. Each large fold is composed of a number of 

 smaller folds having parallel axes, and changing in 

 pitch more frequentiv than the larger folds. Strike- 

 faults of considerable magnitude range nearly parallel 

 with the folding axes, and are in all cases overthrusts 

 towards the east. Of interest are the transverse faults 

 ranging nearlv east-north-east and west-south-west. 

 Two of these faults, the Pennal and Llyfnant Faults, 

 are shatter-belts. The Llyfnant Fault displaces several 

 folding axes, and overthrusts to the east on the north 

 side. Its vertical displacement is on an average about 

 300 ft., but its horizontal displacement is usuallv more 

 than -^oco ft. It mav therefore be called a "tear- 

 fault." — Dr. A. H. Cox: The geology of the district 



