Fekruary 2o, 1902] 



NATURE 



381 



Dr. W. C. C. Pakes, who has been appointed bacteriologist to 

 the Tran'ivaal Ciovernment. The council has resolved that, in 

 order to keep a permanent record of the legacy left to the college 

 by Mrs. Morton Stimner, the lecturer in geology be hereafter 

 called the Morton Sumner lecturer in geology. 



Tut: papers read at the recent conference of science teachers, 

 arranged by the London Technical Education Hoard, are 

 appearing in the Tcchniial Ediaa'ion Gazelle, with reports of 

 some of the speeches. The January number of the Gazelle 

 contains addresses on the teaching of hjgiene, by Miss A. 

 Kavenhill ; mental school hygiene, by Dr. F. Warner ; and 

 the teaching of natural history, by Mr. F. E. Beddard, F.R.S. 



The Technical Education Board of the London County 

 Council report that the reorganisation of London University is 

 already having a marked influence for good on the polytechnics 

 and other institutions. The advanced classes in science and 

 engineering are being revised and brought up to a higher 

 standard, gaps in the curriculum are being filled up, and more 

 students are being induced to enter upon systematic courses of 

 study, extending over three or four years, instead of attending 

 isolated classes. Complete degree courses, under teachers of 

 the University, will shortly be available for evening students at 

 several of the polytechnics. The due recognition ol engineering 

 and higher commercial subjects was provided for by the estab- 

 lishment of separate faculties, and the Senate has now approved 

 courses ol study in which students will proceed to the degrees 

 of B.Sc. and D.Sc. The regulations for the economic or com- 

 mercial degree enable it to be gained in such subjects as the 

 history, principles and organisation of banking, insurance, rail- 

 way and shipping transportation, international commerce, local 

 government, statistics, &c. By means of the Council's aid, the 

 Senate has now determined on (i) the organisation of an insti- 

 tute of advanced chemistry, both organic and inorganic, at one 

 centre ; (2) the provision of advanced teaching in engineering 

 at two centres; (3) the systematic organisation of the teaching 

 of modern languages at all the University centres, including the 

 polytechnics, and beginning with German ; (4) the provision of 

 a professorship of education in connection with the Council's 

 proposed day training college for teachers ; and (5) the appoint- 

 ment of University teachers in economic history and theory, 

 commercial geography and history, banking, statistics, foreign 

 trade, &c. 



SCIENTIFIC SERIAL. 



Bulletin de I'AcadJmie de Sciences de St. Pc'lcrsbonrg, 5th 

 series, vol. xii. — On the compound (so-called stationary) radiants 

 of shooting stars, by Th. Bredikhine (in French). The supposed 

 existence of stationary radiant points (or radiant points of long 

 duration) is an obstacle against all more or less admissible 

 theories of shooting stars. Taking advantage of the 91S 

 meteoric orbits calculated by J. Kleiber in 1S91, and of subse- 

 quent data, the author concludes that each stationary (or long 

 duration) radiant consists of .several individual radiants, even 

 when these radiants do not much differ from each other in their 

 dates ; this means that each stationary radiant is a compound 

 radiant which originates from several individual radiants, each 

 of which has its own position in space and its own origin, 

 and all of which are intersected by the orbit of earth. Thus, in 

 the well-known radiant ofSPersei he finds "thirteen or fourteen 

 different orbits, i.e. as many different streams " (p. 102). The 

 author examines next the theories of Profs. H. H. Turner and 

 A. S. Herschel, and concludes that " the deductions of Prof. 

 Turner are only admissible under the impassible supposition that 

 the earth moves with a uniform speed along a straight line. 

 But if the theory it.self is inconsistent, its secondary complica- 

 tions, such as the spinning of the rieteoritic stream, the resisting 

 medium, &c., have no more signification" (p. 115). Applying 

 his explanation next to the polar stationary radiants of Mr. 

 Denning, the author shows that in the radiant CDraconis (No. 36 

 of catalogue A), one may recognise " twelve different individual 

 streams (twelve comets) apparently composing one single 

 stationary radiant." The author's final conclusion is: — "A 

 stationary radiant does not originate from a single individual 

 stream or from one single comet ; it must be named a compound 

 radiant, because it is produced by several comets or independent 

 streams. The phenomenori is so simple that all complicated 

 and artificial theories are useless and superfluous. . . . Thanks 



NO. 1686, VOL. 65I 



to the numerous and careful observations of Mr. Denning, the 

 phenomenon has lost its supposed individuality and has become 

 decomposable and explicable." — On photographic observations 

 of the satellite of Neptune at Pulkova, by S. Kostinsky 

 (Russian : with a plate). — Report on zoological researches at 

 Sebastopol in 1S99, by A. Kovalevsky : hypodermal fertilisation 

 with the leeches ; on Balraeobdella lalas/ii ; on Hedyle Tyrtowii 

 (n.sp. ); on Psendovermis paradoxus, Periasl. — On faint lines 

 in stellar spectragrams, by A. Belopolsky. — On a MS. in 

 Coptish language attributed to Dionysius Areopagita, by Oscar 

 Lemni. 



SOCIETIES AND ACADEMIES. 

 London. 



Royal Society, January 23. — "Mathematical Contributions 

 to the Theory of Evolution. XL— On the Influence of Natural 

 Selection on the Variability and Correlation of Organs." By 

 Karl Pearson, F. Iv.S. 



The influence of directed — natural or artificial — selection on 

 the characters of a race is one which it is fundamental for the 

 purposes of evolution to appreciate quantitatively. I have 

 already shown in an earlier memoir of this series the effect of 

 random selection, or what it is better to term random sampling, 

 on the characters of a population. Isolation of a few indi- 

 viduals who form a random sample may produce very sensible 

 modifications of race characters, but it is to directed selection 

 that we nmst look for changes on the largest scale. The subject 

 is a very broad and complex one — no less than the total effect 

 upon a population containing individuals at all ages of a selec- 

 tive death-rate applied for a long period and a function not only 

 of the organs of each individual, but of the relationship of 

 these organs to each other, and of the stage of growth of the 

 individual. In the present memoir, attention is confined to the 

 influence of selection in altering a complex of organs, no repro- 

 duction taking place during the selection. 



A very definite distinction is at once reached, namely, that 

 between directly and indirectly selected organs. It may be 

 said that, although it is possible lor the recruiting sergeant tc 

 select stature, and in so doing difierentiate the arm length of his. 

 troop from that of the general population, yet that in natural 

 selection we are given only the modified organs, and so we 

 cannot tell which of them have been directly and which in- 

 directly selected. Both are changed ; how discover which was 

 the source of the change ? The answer is : In the same manner 

 as we could distinguish between two recruiting sergeants, one 

 of whom selected his troop from the general population by 

 stature, and the other by cubit ; in either case the stature and 

 cubit would be both modified, but the mathematical theory of 

 regression would enable us to distinguish between the methods, 

 of operating of th« two men, and even between them and one 

 who selected by both stature and cubit at once. The mathe- 

 matical theory as developed in this paper shows us that, although 

 the whole complex of characters may have been changed, still, 

 if direct selection has only occurred in p out of n possible 

 cases, there will be certain of the partial regression coefticients 

 which remain unmodified and which will theoretically enable us 

 to distinguish among the whole group of differentiated organs, 

 between those directly selected and those modified only because 

 they happen to be correlated with the directly selected organs. 

 Thus the distinction becomes one of singular importance, for 

 though the selection of a few organs modifies the means, varia- 

 bilities and correlations possibly of the whole complex of 

 characters, certain functions of those quantities remain constant, 

 and such constants ought to be discoverable, at any rale in theory, 

 and should serve as the criterion of a common origin, when we 

 deal with local races as having been subjected only to a selection 

 directly differentiating a comparatively few characters. 



If .selection has changed a race from a condition A to a con- 

 dition B, it becomes of much interest to determine the nature 

 of the selective death-rate by which the process has been- 

 carried on, and it is found that this death-rate as represented in 

 the surface of survival rates enables us to distinguish two kinds 

 ol selection, termed in the memoir positive and negative selec- 

 tion. In the first case, a race is modified, because the nearer its 

 members are to having their organs with a certain system of 

 values, the better fitted they are to survive ; in the second case,, 

 the nearer the individuals are to this system the less fitted they 



