6oo 



NATURE 



[October 15, igoS 



As regards inequalities of period over twenty years, 

 Prof. Brown has thrown no fresh light upon the 

 matter. Let us say quite plainly that we do not 

 believe this to be Prof. Brown's fault. We do not 

 doubt that his work is accurate, and because he has 

 not explained certain long-period inequalities which 

 appear to exist, we believe that the cause of those 

 inequalities is something outside the problem that 

 Prof. Brown proposed to himself. Nevertheless, we 

 have only to look down the list of mean errors for 

 each of the last fifty years to see that there still exists 

 some unsolved mystery. 



The mystery becomes greater the further we go 

 back. Prof. Newcomb has investigated and is still in- 

 vestigating the occultations of the seventeenth and 

 eighteenth centuries. In 1883 an empirical correction 

 was introduced into the ephemerides to satisfy these 

 occultations, and Prof. Brown's researches 'do not 

 bring forward any fresh term that will take the place 

 of Prof. Newcomb's empirical term. 



If we go further back still, matters are worse. 

 Many years ago Prof. Celoria traced the eclipses of 

 1239 and 1241 across Europe, collecting records from 

 large numbers of different sources, and he pointed out 

 a disagreement with the paths as calculated from 

 Hansen's tables. The discordance becomes more 

 accentuated as we go further back, until Prof. New- 

 comb declared that all records of ancient solar 

 eclipses were to be put aside as untrustworthy. We 

 do not think that this conclusion will stand, for two 

 or three investigators have shown that the discord- 

 ance between the records and the tables is not hap- 

 hazard, but obeys an empirical law to which different 

 forms may be given, but which is in its effect upon 

 eclipse tracks very much the same in the different in- 

 vestigations referred to. Our conclusion, therefore, 

 IS that a splendid mathematical achievement has 

 been performed, but that our power of predicting the 

 motion of the moon has not been increased in a corre- 

 sponding degree. 



PRO'S AXn COX.'S OF DARWLXISM. 

 (.1) Selcctionsprindp unci Probleme der Artbildiini; .- 

 em Haudbiich des Darwinisinus. By Prof. Ludwig 

 Plate. Dritte, sehr vermehrte Auflage. Pp. viii + 

 493; 60 figs. (Leipzig: W. Engelmann, igoS.) 

 Price 12 marks. 

 (2) Die Lehre Darn'ins in ihrcn letzten Folgen. By 

 Max Steiner. Beitrage zu einem systematischen 

 .Ausbau des Naturalismus. Pp. vii + 244. (Berlin: 

 Ernst Hofmann and Co., 190S.I Price 3 marks. 

 (I) pROF. L. PL.ATE'S " Selektionsprinzip " has 

 -L been so much expanded in its third edition 

 that^ it deserves to be called " a handbook of Dar- 

 winism." It is a careful and thoughtful text-book by 

 a thorough-going Darwinian, who is at the same time 

 a believer in the transmission of acquired characters. 

 In the first chapter he considers the objections to 

 Daiwinism. These may be relatively unimportant, 

 c-.s,'. that Darwinism does not account for the origin 

 of variations, that artificial and natural selection are 

 not really analogous, that the struggle for existence 

 is not selective. But there are other objections which 

 >>'0- 2033, VOL. 78] 



aro more essential, e.g. that minute changes cannot 

 have selective value, that the process of natural selec- 

 tion cannot be seen occurring, that the theory of 

 selection starts from, the fortuitous. It is useful to 

 have a modern Darwinian's answers to these and 

 other attacks on his faith, and it is much to be desired 

 that those who rush into print \vith anti-Darwinian 

 books and essays would read a work like Plate's, 

 especially if they will not read Darwin. 



The second chapter gives a careful discussion of the 

 various forms of struggle and selection. The third 

 discusses the auxiliary, or would-be auxiliary, theories 

 — theories of sexual selection, struggle of parts, 

 panmixia, germinal selection, and mutation ; and the 

 author deals in a strongly critical but temperate 

 Tuanner with the difficulties which beset these. He 

 will have nothing to do with germinal selection and 

 not much with Roux's " Kampf der Telle"; pan- 

 mixia may account for degeneration, but not for rudi- 

 mentation, and most of what is new in the mutation- 

 theory is not true. .Apart from .selection, the 

 conditions of evolution are heritability, variability, and 

 isolation ; and the discussion of these is admirable. 

 One may not agree — and we certainly do not feel in 

 any way convinced by the author's vigorous Lamarck- 

 ism — but one must admit that the author's presentation 

 is skilful and Just. He states the experimental and 

 other facts which lead him to think that we cannot 

 dispense with modification -inheritance, and he 

 sketches a hypothesis, not unlike Herbert Spencer's, 

 of the passage of a specific influence from the peri- 

 pheral parts of the soma to the penetralia of the 

 geim-cells. Plate is far from thinking that the 

 selection-theory clears up everything ; it starts with 

 growing and multiplying organisms which it does not 

 explain ; the conditions of variability and inheritance 

 are still unknown ; there are many unsolved problems. 

 But instead of making a harsh alternative between 

 the " Allmacht " or " Ohnmacht " of natural selec- 

 tion, what we have to do, as the author well indicates, 

 is to test this and other formulae in a critical yet fair- 

 minded fashion. This is what he has aimed at in his 

 book, and it seems to us that he has succeeded well, 

 on the whole, at any rate, for now and again, e.g. in 

 his remarks on the vitalists, he seems to us to be 

 unnecessarily hot-blooded. We should like to know, 

 for instance, where Dr. Hans Driesch spoke of a 

 " Degeneration des Gehirns der Darwinisten." Is 

 this not a fictitious quotation? 



(2) The author of the second volume before us 

 seems to think that Darwinism has been too much 

 discussed as a biological theory, artificially abstracted 

 from its social consequences. If we understand him, 

 he seeks to put things right by showing what terrible 

 consequences the theory involves. A scientific formu- 

 lation is not to be Judged by its applicability to the 

 order of facts in relation to which it arose — that is 

 a humdrum conventional inquiry which may be left 

 to men like Prof. Plate — it must be Judged by its 

 human consequences ! So Herr Steiner expounds 

 with gusto his by no means favourable Judgment of 

 the metaphysic and ethic of Darwinism and its bearing 

 on aesthetics and the valuation of life. He shows to 



