55 8 SCIENCE PROGRESS 



favour is that it was plausible and that by implication it recognises the wonderful 

 adaptation of structure to function. 



Besides these theories the book contains notable improvements in classification 

 among other good things ; the essential differences between vertebrates and in- 

 vertebrates are first definitely established ; Crustacea and Arachnida are separated 

 from Insecta ; annelids set apart from the remaining "worms"; and infusorians 

 (our modern Protozoa) removed from polyps, and recognised as the lowliest 

 members of the animal kingdom. Throughout the book it is repeatedly urged 

 that all problems must be attacked by the scientific method, and this is applied 

 to numerous questions, still being discussed in biology, with a varying degree 

 of success. The many points raised cannot be adequately dealt with here, and 

 the reader is referred to this volume, which may be recommended as a very 

 faithful rendering of the original. It is throughout well written and carried 

 out in an able and conscientious manner. 



C. H. O'D. 



An Introduction to the Study of Plants. By F. E. Fritsch, D.Sc, Ph.D., 

 and E. J. Salisbury, D.Sc. [Pp. vi + 397, with 8 plates and 222 figures 

 in the text.] (London : G. Bell & Sons, Ltd. Price 4^. 6d. net.) 



To plan an elementary course of instruction in Botany in which the subject-matter 

 is arranged in logical sequence, so that the course shall not degenerate into a 

 disconnected series of lessons, is probably more difficult than in the case of other 

 science subjects. The most obvious cause of this difficulty is an unavoidable one 

 — the seasonal periodicity of plant-life ; the teacher must use what materials 

 are available at different times of the year. Again, it is generally realised that if 

 Botany is to remain an educationally valuable as well as attractive subject, form 

 and function must be correlated throughout an elementary course ; and since 

 the physiology of plants, like that of animals, depends largely upon chemical and 

 physical processes, a practical acquaintance with the elementary facts of Chemistry 

 and Physics is essential for the proper understanding of the functions of plants. 

 Yet many students begin work in Botany with little or no previous knowledge of 

 these subjects, and the teacher must do what is possible to remedy the defect. 



If the planning of a satisfactory course of work in elementary Botany is a 

 difficult task, that of writing a book which shall reflect such a course is very much 

 more so. Professor Fritsch and Dr. Salisbury have succeeded in producing the 

 nearest approach to the ideal elementary botanical text-book that we have en- 

 countered. In the preface they make the modest claim that they have gone 

 beyond the usual scope of an elementary introduction to plant-life by including 

 a chapter on the soil and a fairly detailed account of plant-communities. The 

 latter certainly forms a very attractive feature, for in no other general elementary 

 work have we found such a well-written and well-illustrated account of the 

 vegetation of woodlands, heaths, moorlands, ponds, streams, and the sea-coast. 

 But in every part of the book one is impressed by the careful and skilful treatment 

 and arrangement of the subject-matter— the care and skill which make a book 

 easy reading for beginners, while keeping it strictly accurate and scientific 

 throughout. In every respect it is a thoroughly satisfactory introduction to 

 Botany, and if we have any fault at all to find with it, it is that rather too much 

 is done for the student, especially as to illustrations. However, the book is not 

 merely one for students in schools and colleges ; it is one that can be warmly 

 recommended to all who are interested in plant-life. 



This book will undoubtedly make and maintain a prominent place of its own 



