Febkuaky 21, 1908] 



SCIENCE 



307 



The book also considers the various attempts 

 that have been made to improve the equation 

 of van der Waals, and the equations of state 

 proposed by others. The last chapter gives 

 the mathematical methods by which the equa- 

 tion of van der Waals may be deduced. 



The book is a valuable monograph on the 

 subject of which it treats and brings together 

 a large amount of information that otherwise 

 could be found only by a laborious search 

 through journals. At the end of each chap- 

 ter, and in footnotes, are given full references 

 to the literature of the subject treated of in 

 the chapter. At the end of the book there is 

 an index of names but not of subjects. The 

 need of a subject index is satisfied in part by 

 a full table of contents in the front of the 

 book. A book of this kind, however, has a 

 valuable use as a reference book, and for such 

 a use the lack of a good subject index is a 

 serious shortcoming, which is felt keenly in 

 proportion to the value of what the book con- 

 tains. It is only a book to which no one 

 wishes to refer that does not need a subject 

 index. W. S. D. 



Plant Anatomy from the Standpoint of the 

 Development and Functions of the Tissues 

 and Handbook of Micro-technic. By W. 0. 

 Stevens. 8vo. Pp. xii -f 349. With 136 

 illustrations. Philadelphia, P. Blakiston's 

 Son & Co. 1907. 



As is indicated by the title of this book, the 

 standpoint adopted is the physiological one; 

 in fact, the book might have been named 

 Anatomical or Structural Physiology. The 

 titles of many of the chapters indicate this, 

 e. g.. Construction of the Plant's Food, Secre- 

 tion and Excretion, and the general method 

 of discussion is to describe the process, then 

 the structures concerned. No doubt this is a 

 useful standpoint, and the method of treat- 

 ment is appropiiate, but it seems a pity that 

 the bearing of anatomy on the great problems 

 of morphology should be altogether ignored. 

 Since the book is in no sense a work on com- 

 parative anatomy, we find no reference to the 

 structure of fossil plants. 



Within the scope of 217 pages the author 

 gives a clear though necessarily brief and ele- 



mentary account of the main processes and 

 structures of the so-called vegetative parts of 

 a higher plant. The first three chapters de- 

 scribe the development of the tissues from the 

 undifferentiated cell, through the stages of 

 meristem, primary structure and secondary 

 growth. In the main the account is clear and 

 accurate as far as it goes, and is much aided 

 by the carefully executed and elaborate dia- 

 grams which illustrate such features as the 

 primary and secondary structure of stems. 

 The diagrams throughout the book are in fact 

 one of its most noteworthy and valuable fea- 

 tures. The description of vascular bundles 

 may be adequate from the author's standpoint, 

 but it seems strange to see no reference to 

 protoxylem, nor figures of amphicribral and 

 bicoUateral bundles. Several Well-chosen " il-- 

 lustrative studies " conclude each chapter. 



Protection from Injuries and Loss of Water 

 and The Plant Skeleton are next considered. 

 The treatment here is too brief and incom- 

 plete to give the student an intelligent idea 

 of the important ecological adaptations which 

 might be discussed under these heads. Loss 

 of water through stomata is not treated here, 

 as one might expect, but is deferred to a later 

 chapter. 



The absorption, circulation and storage of 

 water, gases and foods are the topics discussed 

 in chapters VI. to XL By means of numer- 

 ous ingenious diagrams the leading facts are 

 presented in so lucid a way that he who runs 

 may read. A possible exception to this state- 

 ment may be found in Pig. 94, in which the 

 perspective is faulty. Moreover, it may be 

 questioned whether this diagram as well as 

 some others does not try to show too much. 

 Owing to the standpoint of the book we might 

 expect to find under the heading of circula- 

 tory tissues some reference to Strasburger's 

 brilliant discovery of the substitutes for com- 

 panion cells in the phloem of Pinus, but in- 

 stead of this we find the erroneous statement 

 (p. 162) : " In gymnosperms and vascular 

 cryptogams the companion cells do not occur, 

 and their place is taken by vertical rows of 

 parenchyma cells." A series of illustrative 

 studies concludes each chapter of this section. 



A chapter on Secretion and Excretion con- 



