-May 6, 1969] 



NATURE 



275 



The author decides in favour of a rotation period 

 for both Mercury and Venus approximating to that 

 ■of the earth. He gives an excellent resume of Prof. 

 Poynting's investigations of temperature. He obtains 

 for Mercury 193° C, for \'enus 66° C, and for the 

 earth, by the same method, 16° C. This last result 

 inspires some confidence in the two former. M. 

 Andr^ decides against the canals of Mars. It is one 

 of the many evidences of the up-to-date character of 

 the book that reference is made to the experiments 

 by Mr. Maunder and Mr. Evans on this question with 

 the help of the boys of the Royal Hospital School at 

 Greenwich. 



The chapter on minor planets is excellent. M. 

 Mascart has, however, recently covered the same 

 ground. The present volume contains a reference 

 to 1906 TG. The chapters on Uranus and Neptune 

 consist for the most part of what is now ancient 

 history. The author considers that planets inside 

 Mercury or outside Neptune would have been already 

 discovered if they existed. 



In the second part the author gives a historical 

 account of various announcements of a satellite of 

 Venus. His chapter on the satellites of Mars, and 

 the first half of the following chapter, is necessarily 

 somewhat hackneyed. The latter chapter concludes 

 with Mr. Melotte's discovery of Jupiter's eighth satel- 

 lite and Mr. Crommelin's announcement that the 

 orbit was retrograde (fait ahsolument inattendu). Mr. 

 Crommelin's original period of three years and a 

 half, based on the supposition of a circular orbit, 

 enables one to date the writing of this paragraph to 

 within a month or two. 



The interest of the next chapter centres on Phoebe 

 and the still unconfirmed tenth satellite. The last 

 chapter of tRe second part refers to the masses of 

 the planets and their satellites. 



The third part, on the formation of the planetary 

 system, describes Laplace's nebular hypothesis and its 

 subsequent extensions and modifications by Roche, 

 Darwin, Faye, and Stratton. On p. 239, in four 

 short paragraphs, we have a statement of the case 

 against Laplace's hypothesis. In these paragraphs 

 the retrograde motion of Jupiter's eighth satellite is 

 again mentioned. 



The Care of Natural Monuments, with Special Refer- 

 ence to Great Britain and Germany. By Prof. H. 

 Conwentz. Pp. xi+185; illustrated. (Cambridge: 

 University Press, 1909.) Price 2^. 6d. net. 

 The title of this little work scarcely gives a sufificient 

 clue to the nature of its contents, as there are com- 

 paratively few persons who would regard wild 

 mammals or wild birds as "natural monuments." 

 As he tells us in the introduction, the author has 

 himself felt this difficulty, but has nevertheless used 

 the term as a translation of the German " Natur- 

 denkmal "; though we fear this rendering may result 

 in checking the sale of an excellent and praise- 

 worthy volume. Prof. Conwentz writes as one having 

 authority, since he is the Prussian Government com- 

 missioner for the care of natural monuments. On 

 this subject he delivered an address at the Leicester 

 meeting of the British .Association in 1907; and it is 

 that lecture which forms the groundwork of the book 

 now before us. The book is divided into two sections — 

 '' Nature Threatened " and " Nature Protected " — 

 the former particularising the various natural objects 

 and types of scenery which require protection, and 

 the latter what has been and is being done in this 

 direction in different countries, but more especially 

 in the United Kingdom and Germany. On the whole, 

 the author appears to consider that we are doing our 

 duty as regards the protection of the indigenous fauna 



NO. 2062, VOL. 80] 



fairly well, and bestows unstinted commendation on 

 the action of local authorities in establishing reser- 

 vations in various parts of the country. He is, how- 

 ever, of opinion that more attention might be devoted 

 to securing small areas as reserves of this nature ; 

 and as regards other " natural monuments " suggests 

 that private landowners might be induced to do 

 more in the way of conservation than is at present 

 the case. It is also suggested that the central com- 

 mittee for the study and survey of British vegetation 

 might include in its programme the protection of 

 characteristic associations of plants, as well as of 

 single rare species. By directing attention to what 

 has been done and what remains to be done, the 

 appearance of the volume will doujjtless serve to 

 awaken renewed interest in the subject. R. L. 



The Mineral Kingdom. By Prof. R. Brauns. Trans- 

 lated, with additions, by L. J. Spencer. With 91 

 plates (73 of which are coloured). (Stuttgart : 

 Fritz Lehmann ; London : Williams and Norgate, 

 1908.) Parts i. to v., price 2S. net each. 

 While popular introductions to botany and zoology 

 are numerous and find a ready sale, little has been 

 done to familiarise the general public with the ap- 

 pearance and characters of the commoner minerals. 

 The chief obstacle has been found in the difficulty 

 of depicting the colour and lustre of minerals so 

 accurately that they may be recognised without the 

 employment of the ordinary methods of determination. 

 To judge by the five parts which have already 

 appeared an unusually successful attempt has been 

 made in the present work to solve the problem of 

 the representation of minerals by colour printing. 

 The reproductions of topaz, tourmaline, and phos- 

 genite are excellent, and even minerals with metallic 

 lustre are in most cases very effectively rendered. 

 The plates measure 95 inches by 6J inches, and, as a 

 rule, contain numerous coloured figures. 



The book can be recommended to all who wish 

 to take up the study of mineralogy, and have not 

 the opportunity of referring to a collection containing 

 as many examples as those illustrated in these plates. 



The text is clear and readable, and comprises a 

 simple introduction to the principles and methods of 

 the science, as well as a detailed account of the 

 different mineral species. J. W. E. 



Man in the Light of Evolution. By Dr. J. M. Tyler. 



Pp. xiv+231. (London: Appleton and Co., 1909.) 



Price 6s. net. 

 This is the sort of book about which there is no need 

 to say anything harsh. It is calculated to produce 

 a vague edification in the mind of the unscientific 

 reader. Prof. Tyler's attitude towards disputed 

 problems of evolutionary science is so conciliatory and 

 non-committal that one fails, ' for instance, to dis- 

 cover what view he holds about the inheritance^ of 

 acquired characteristics, or whether he has any view 

 of his own. He alludes in a distant way, but always 

 politely, to Mr. Darwin, Mr. Haeckel, and so on. 

 (But why is poor Mr. A. J. Balfour "Balfour"?) 

 So far as he has any point to make, it would seem to 

 be this, that the springs of progress lie not so much 

 in the environment as in our own " higher powers," 

 and that these " higher powers " consist especially in 

 our .moral and religious tendencies. All this may be 

 quite true; but it cannot be said that our author 

 helps in the slightest degree towards a clear under- 

 standing either of what those are or of how they 

 have come about. A perfectly worthless bibliography 

 is appended, in which the name of J. M. Tyler appears 

 more than once, but that of E. B. Tylor not at all. 



