June 6, 1907] 



NATURE 



125 



compilation, has been ably presented by Dr. Davis. 

 He keeps the evolutionary sequence constantly before 

 the student, and directs special attention to the signifi- 

 cance of alternation of generations, heterospory, and 

 the evolution of the sporophyte. Under ecology, 

 chapters are devoted to recent work on the origin of 

 species and plant breeding. 



The book can be confidently recommended to 

 students and teachers, and the latter will find the 

 arrangement well worthy of consideration. 



(2) Having devoted special attention to the 

 ecological aspect of botany, Prof. G. Henslow has 

 prepared an introduction to the subject. The earlier 

 pages contain a discussion of methods of teaching 

 botany, and in subsequent chapters the nature of 

 plant associations, modifying factors, and plant 

 surveying are considered. The information is mainly 

 suggestive, and will therefore be found too diffuse 

 for the ordinary student. On the value of ecology 

 as an educational study the author advances argu- 

 ments with which one is in accord, but with regard 

 to certain criticisms on anatomy and physiology it 

 can onlv be inferred that he has not had the oppor- 

 tunity of observing what an excellent training is 

 provided by a judicious laboratory course. 



(3) The main object of the course planned by Mr. 

 E. H. Davies is to enable the learner to obtain his 

 information by his own observation, so that the 

 lessons, except in so far as they give instructions, 

 consist of a series of questions. The assistance re- 

 quired to furnish the answers is contained in a 

 glossary at the end of the book. The detail is well 

 thought out, and if the exercises selected are a trifle 

 too elementary, more difficult ones can be easily 

 substituted. The author very rightly insists on the 

 necessitv of making outline drawings of all objects 

 examined. 



(4) The advantages of a school garden where 

 children ma)' acquire practical l<nowledge are suffici- 

 ently obvious, and in country scliools there should 

 be no difficulty in securing the necessary ground. 

 For teachers who have not the requisite horticultural 

 experience, Mr. Hennesey provides in " The School 

 Garden " just the information required for directing 

 their operations. The laying out of the garden, 

 trenching, propagation, and the cultivation of fruit 

 trees, vegetables, and fiowers are rationally and prac- 

 tically expounded; to these are appended suggested 

 courses of work and general hints as to ways and 

 means. 



The book provides a concise manual of elementary 

 horticultural instruction that may be profitably con- 

 sulted, not only by teachers, but generally by those 

 who grow their own fruit and vegetables. 



(5) A coloured picture-book of flowers arranged for 

 children, so that thev can distinguish them and find 

 out their names, describes the nature of the last book 

 under notice. Arranged according to colour, the 

 illustrations furnish the means of determination. The 

 type and general form of the book are pleasing, and 

 the short descriptions, referring mainly to the flower, 

 are expressed in simple language. 



NO. 1962, VOL. 76J 



OVR BOOK SHELF. 



Ballooning as a Sport. By Major B. Baden-Powell. 



Pp. XX -(-135. (Edinburgh and London: William 



Blackwood and Sons, 1907.) Price 3s. bcl. net. 

 Flying Machines: Past, Present, and Future. By 



.Alfred W. Marshall and Henry Greenly. Pp. 128. 



(London : Percival Marshall and Co., n.d.) Price 



K?. net. 

 Major Baden-Powell himself, in a chatty introduc- 

 tion, describes his book as a rechauffe of a few maga- 

 zine articles - mostly written some years ago. The 

 essavs deal with the past of ballooning pure and 

 simple, but their bright conversational style will com- 

 mend them to a wide circle of readers. 



The second little volume provides a popular account 

 of flying-machines, dirigible balloons, and aeroplanes. 

 Mathematical formulae and calculations for designs 

 have not been included, though the authors say thev 

 intend their information to " assist the reader with 

 serious intention of making an attempt to produce 

 a flying-machine, or air-ship." The book is fullv 

 illustrated, and should prove of interest to the general 

 reader. 



Principes de Giologie stratigraphique, avec DH'elophe- 

 tnents sur le Tertiaire parisien. By G. Courty. Pp. 

 xiv + 78. (Paris: .\. Hermann, igoy.) 

 Those who look on Lyell's " Princioles of Geologv " 

 with a filial regard, and those who keep by them Dr. 

 Marr's scientific introduction to stratigraphy, will be 

 disappointed with the title of this little book, which 

 deals with elements rather than with what we know 

 in this country as principles. Prof. Stanislas Meunier 

 contributes a preface, in which he dwells on the con- 

 stantly changing character of the earth's crust; and 

 the author also holds that his work contributes towards 

 the realisation bv the reader of this " vitalite tel- 

 luriaue." But we are given little else than a summary 

 of what is to be found in an ordinary text-book, and 

 no attempt is made at generalisation. For a French 

 work this is remarkably void of inspiration. 



Outlines of Practical Sanitation. By Dr. H. B. 

 Bashore. Pp. vi-(-2o8. (New York: J. Wiley and 

 Sons; London: Chapman and Hall, 1906.) Price 

 55. 6<i. net. 

 The scientific principles of public health and personal 

 hygiene are explained in a simple and attractive 

 style in this volume. Though the author refers par- 

 ticularly to conditions in rural and urban districts of 

 the United States, his descriptions are concerned in 

 the main with considerations of causes affecting 

 health in general, both of the community and the in- 

 dividual. " Familiarity with the principles described 

 ought to be regarded as an essential qualification of 

 every member oi a sanitary committee of a public 

 body. The book should be 'found useful as a means 

 of imparting sound ideas of the laws of healthy living 

 to teachers and citizens. 



Essay on the Creative Imagination. By Th. Ribot 

 Translated from the French bv Albert H. N. Baron. 

 Pp. xix-l-370. (Chicago: The Open Court Publish- 

 ing Co. ; London : Kegan Paul, Trench, Triibner 

 and Co., Ltd., 1906.) 

 The translator, enumerating some of his reasons for 

 translating M. Ribot's essay, summarises the results 

 at which it arrives by stating the author has shown 

 clearly that " imagination is a function of rnind 

 common to all men in some degree," and that it is 

 as highly developed in " practical inventors as in the 

 most bizarre of romantic ide.-ilists." The chapter on 

 the scientific imagination will appeal especially to the 

 student of science. 



