250 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



with the scheme of the series, the author has confined himself chiefly 

 to his own investigations in the particular line of research with which 

 the subject-matter deals. 



Mr. Lawrence Ball is botanist to the Egyptian Government 

 Department of Agriculture, and this book contains an abstract of the 

 results of a series of researches he has made upon the cotton plant 

 in Egypt. The problems he set himself to solve were numerous and 

 diverse, and the care and knowledge displayed in the investigations 

 are worthy of all praise. In the preface we are told that the work 

 began as genetics but extended into physiology. The physiological 

 researches were necessitated by demands for information as to the 

 effect of unsuitable soil-water conditions (cotton being an irrigated 

 crop in Egypt) on the cotton plant, and these have given results of 

 more immediate interest, and greater novelty, than the researches 

 concerned with genetics, although the latter may eventually prove 

 of higher intrinsic value. The physiological researches have shown 

 that a high water-table is harmful to the cotton crop at certain seasons, 

 and, to obviate this, drainage and a restricted irrigation are now being 

 applied. The breeding experiments on Mendelian lines have thrown 

 much light on the causes of the deterioration of the Egyptian cotton, 

 and the author insists, as a result of these experiments, that any 

 scheme for the improvement of the stock by the introduction of new 

 varieties is doomed to failure unless care is taken to prevent con- 

 tamination, by renewing continually the supply of the pure strain. 



The importance of the cotton crop both to England and Egypt 

 cannot be over-estimated, consequently any contribution to a more 

 complete knowledge of the plant and its requirements is of the 

 greatest value. This book, besides adding to our knowledge of 

 the cotton plant itself, contains much that will appeal to the student 

 of plant physiology, while the Mendelian will find the results of the 

 breeding experiments of great interest. 



" Soil Conditions and Plant Growth." By E. J. Russell, D.Sc. 

 8vo. viii -f 168 pp. (Longmans, Green, London, 1912.) 5s. net. 



Recent research in soil chemistry, physics, and biology has greatly 

 extended knowledge of the conditions existing in the soil as they affect 

 plant life, and a book giving the results of these researches, fitting them 

 into their places in the general scheme, and doing it all in such a 

 masterly and lucid fashion as is the case here, will meet with a hearty 

 welcome from all concerned in teaching soil science, and from those 

 who base their practice on as full a knowledge of soil and plant life 

 as is attainable rather than on the practice of their neighbours as seen 

 by looking over the hedge. To all such we commend it. The main 

 problems dealt with are the requirements of plants and the constitu- 

 tion of the soil ; the carbon and nitrogen cycles in the soil ; the 

 biological conditions in the soil ; the soil in relation to plant growth ; 

 soil analysis and its interpretation. An appendix gives the methods 



