676 SCIENCE PROGRESS 



odder grasses such as species of Aristida and Eragrostis . Again, in the Eastern 

 grass-veld, characterised by a summer rainfall, the chief grasses are the Red 

 Grass and Thatch Grass (Andropogon hirtus), but here too the same causes may 

 prevent the complete succession, with the result that inferior pioneer species 

 become dominant {e.g., Aristida junciformis, A. congesta, Sporobolus indicus, and 

 Eragrostis spp.). 



In the concluding chapter, which deals with economic applications, the im- 

 portant effects of grazing, burning, overstocking, etc., and their influence on the 

 composition of grassland, are considered. With regard to burning, the author 

 emphasises the fact that the effect produced is dependent on the time of the year 

 and the particular phase of succession reached when the operation is carried out. 



An appendix furnishes a list of the English, Dutch, Zulu, and Sesuto names of 

 the grasses with their corresponding Latin binomials. 



To those interested in South African grasslands the work has its greatest value, 

 but it also has a wider claim as emphasising the economic importance of ecological 

 investigations. 



E. J. Salisbury. 



The Botany of Crop Plants. By Wilfred W. Robbins, Ph.D., Professor of 

 Botany, Colorado Agricultural College. [Pp. xx + 68 1, with 263 figures 

 in the text.] (Philadelphia: P. Blakiston's Son & Co., 1917. Price $2.00 

 net.) 



This work is intended to give the botanical student both in agricultural and non- 

 agricultural schools a presentation of the botany of the common crop plants, 

 including those of the garden and orchard. It consists of two parts, the first of 

 67 pages giving a general outline of the morphology of the flowering plant, and 

 the second, which comprises the greater part of the book, consisting of descrip- 

 tions of the various species of crop plants. 



The object of Part I. is to refresh the student's acquaintance with the funda- 

 mental facts of plant structure, or to serve as a preparation for Part II. The author 

 states in his preface that in many institutions Part II. will be preceded by a general 

 course in the principles of botany which will give the student a survey of the plant 

 kingdom, in which case Part I. will be omitted. It is to be hoped that this will 

 very generally be the case, for Part I. only deals with the flowering plant, and it 

 is very desirable that students, as a rule, should have a more general knowledge 

 of the plant kingdom than that provided by Part I. before turning to the 

 specialisation involved in the study of the subject matter of Part II. 



Part II. has been written especially to meet the requirements of North 

 American students, and does not by any means deal with all crop plants. 

 Nevertheless, one cannot fail to be impressed by the large number of species with 

 which the author deals. Certainly the great majority, and perhaps all, British 

 crop plants find a place here, and the book will be useful on this side of the 

 Atlantic for this reason, as well as for the information it gives of species which are 

 not cultivated here. As examples of these latter may be mentioned the species 

 of Sorghum, which are favourite objects of research in America, but with which 

 most British readers are unacquainted. 



In the description of the various species of crop plants the morphological 

 features are adequately dealt with, although in many cases more might have 

 been made of the physiological and economic aspects of the species. 



The book is well illustrated, while the list of references to literature at the end 

 of each chapter should prove useful to those desiring further information on 



