NATURE 



[July 6, ign 



of any one of them (i.e. two units) will double (or 

 halve) the rate at which any particular substance, the 

 action of which on the cell it is desired to study, will 

 be absorbed. The method is a neat one, but it 

 possesses obvious drawbacks, unless the separate action 

 upon the cell of its constituents in the different 

 strengths employed is fully known. The formulae 

 employed present an unfamiliar appearance, as the 

 factors are all added together, and the inclusion 

 amongst them of time- and heat-factors, on the basis 

 of units composed of ten minutes and 5 C. respec- 

 tively seems to assume unusual simplicity in the 

 reactions involved. 



By means of this method, however, depending 

 largely on the entrance of the stain to the 

 nucleus, many surprising results were obtained. 

 The addition, for example, of various alkaloids, 

 putrefactive products, &c, led the author to 

 formulate far-reaching conclusions as to the 

 causes underlying cell division, with the result that 

 he believes himself to be justified in announcing the 

 discovery of the main causes that bring about cell 

 division, and induce cell proliteration. The causal 

 agents in question are, of course, chemical, and prob- 

 ably most people who have paid any attention to the 

 matter would agree with Mr. Ross that the funda- 

 mental causes of mitosis (nuclear division) are 

 assuredly of a chemical nature. He thinks he has 

 identified certain of these bodies, and this would con- 

 stitute a most important addition to science if his 

 views as to their action on the living cell should turn 

 out to be as well founded as he imagines them to be. 



It is, however, difficult to avoid scepticism on this 

 very point, namely, as to whether the evidence on 

 which the conclusions are drawn is really cogent, and 

 whether the latter are themselves fully warranted. 



The author might himself have contributed towards 

 the solution of these crucial difficulties had he seen 

 fit, in addition to the picturesque presentation of his 

 results, to have subjected the foundations on which 

 they rest to a full and wary criticism. For it is clear 

 enough from the account actually given that the 

 cells, even as they were being examined in the jelly, 

 were moriturient. It is stated, over and over again, 

 that under the conditions of the experiments it was 

 not easy to keep them alive for more than ten minutes. 

 It is not, after all, very surprising to learn that 

 all sorts of movements and distortions followed 

 on the application of drugs like atropin, but 

 it is at least uncommon to find that a 

 mitosis can be completely carried through in three 

 minutes. Numerous examples of alleged "mitosis" 

 are described, and photographs are adduced in support 

 of the descriptions. But the photographs themselves 

 are singularlv unconvincing, and suggest fragmenta- 

 tion or breaking up of the cell as a whole rather 

 than anything one would expect to see in an actual 

 cell- or nuclear-division. We fail to find any critical 

 guard against misinterpretation of phenomena that 

 mipht be due to osmotic differences or to the poisonous 

 action of reagents employed. 



Nor is one reassured by the account of mitosis (i.e. 

 nuclear-division) as referred to in the book. The treat- 

 ment of the whole subject is suggestive of the enthu- 

 NO. 2175, VOL. 87] 



siastic amateur who is simply unable, owing to tem- 

 perament or lack of training, critically to check and 

 examine his own work. Of course, we do not 

 mean positively to assert that such is really 

 Mr. Ross's position, but anyone who puts forward 

 statements on mitosis such as appear on pp. 148 and 

 149, or again on p. 166, without producing the 

 strongest and most convincing proofs, must not com- 

 plain if in other directions his views fail to command 

 unreserved acceptance. We are not at all surprised 

 to learn that when Mr Ross attempted to convince 

 his friend of the soundness of his conclusions by demon- 

 strating to them his preparations they all with one 

 consent, as he himself avers, "began to make excuse." 

 It may be readily admitted that the book contains 

 much that is interesting and valuable by way of sug- 

 gestion, but we do not regard the conclusions of its 

 author on cell-division and cell-proliferation as suffi- 

 ciently well founded. J. B. F. 



THE EVOLUTION OF LUNAR DETAIL. 

 V er gleichende Mond- und Erdkunde. By Prof. S. 

 Giinther. Pp. xi+193. (Braunschweig: F. Vieweg 

 und Sohn, 191 1.) Price 5 marks. 



THE resemblance which exists between the surface 

 of the globe and that of the moon, as shown in 

 the irregularities of level and the general character 

 of the superficial formations, has long attracted atten- 

 tion, and much ingenious speculation has been ex- 

 hibited in tracing a connection and seeking the cause. 

 Fanciful theories exist without number, but men of 

 the highest eminence have occupied themselves w-ith 

 the same theme, being led to it by the fascinating 

 problem of the " Plurality of Worlds." This is the 

 attraction that has induced Prof. Giinther to study 

 the subject, or, perhaps it would be more correct to 

 say, to sift and examine what others have written 

 about it. His book is a marvel of research and a 

 triumph of industry. He seems to have examined all 

 that has been written, whether in fact or fiction, 

 bearing on the relations of earth and moon. Mr. 

 H. G. Wells and Jules Verne represent one school of 

 thought ; Procter and Flammarion another ; the 

 highest authorities, as Darwin, Loewy, and Puiseux, 

 form a third. Every page bristles with notes, and is 

 encumbered by the author's commentaries on those 

 notes. This arrangement perhaps shows greater 

 power of collection than of assimilation. Much of the 

 matter, if worth preserving, could have been incor- 

 porated in the text and made the book easier to read. 

 But however wide the outlook, whether in time or 

 in nationality, problems connected with the physical 

 constitution of inaccessible bodies are likely to remain 

 unsettled, and the discussion prove barren of result. 

 The history of this speculative inquiry is profoundly 

 interesting, but from a philosophical and not an astro- 

 nomical point of view. We are indebted to the author 

 for the skill with which he has marshalled his facts 

 and the enormous amount of information he has col- 

 lected, but the moon seems little likely to contribute 

 any fresh facts of importance to the main issue, since 

 the probability in favour of similarity of structure and 

 of evolutionary history is so great. By whatever pro- 



