REVIEWS 331 



area than any other food crop." A book dealing successfully with such a subject 

 is, then, to be specially welcomed at this time. 



That the authors have succeeded in their object there can be no doubt. 

 Prof. Gilbert states in the preface that the work is written especially "for the 

 practical farmer and the student who may wish for concise information on the 

 potato." It may also be recommended to the purely botanical student and 

 teacher, and its perusal will scarcely be a waste of time to the research worker in 

 plant physiology, who should find much in it that is stimulating and suggestive. 



The introductory chapters dealing with statistics and history are laudably 

 brief, but interesting. The next chapter, which deals with classification, contains 

 a long table of varieties. Here the American standpoint of the book is very 

 evident, for one looks in vain for many well-known British forms, such as Arran 

 Chief and King Edward VII. 



In Chapter IV. the principles of potato breeding are presented in considerable 

 detail, the desirable attributes are discussed, and the methods of attaining im- 

 provement by bud selection, mutation (bud-sports), and crossing are considered. 

 Prof. Gilbert considers the first two methods are within the scope of the practical 

 grower, but wisely recommends leaving the more difficult question of hybridisation 

 to the experiment station. 



One way of bringing about increased productivity is thus by paying attention 

 to hereditary factors ; another way is to influence the environment. The latter is 

 dealt with by Mr. Dean. The most important factors of the environment are 

 temperature and rainfall, which in themselves are largely responsible for the lower 

 yield of the potato in America as compared with Northern and Central Europe. 

 Besides these climatic factors are the soil factors, texture, available plant food, etc., 

 any one of which may act as a limiting factor, inasmuch as it may "place a limit 

 of the size of the crop which cannot be removed by the others being favorable." 



Other chapters deal with tillage and planting, the care of the growing crop, 

 including the control of insects and plant diseases, and with harvesting, marketing, 

 and storage. The various uses of the potato are also discussed, and the book 

 closes with a chapter on the cost of growing potatoes. This latter part of the 

 book is of course particularly applicable to American conditions. 



The book is generally clearly written, although in a few cases there are 

 sentences which leave one wondering what meaning the author intended to 

 convey, as, for example, at the top of p. 7. Such instances are, however, few and 

 negligible. 



W. S. 



The Book of the Rothamsted Experiments. By A. D. Hall, M.A., F.R.S., 

 late Director of the Rothamsted Experimental Station, First Principal 

 of the South-Eastern Agricultural College, now Secretary of the Board of 

 Agriculture. Second edition, revised by E. J. Russell, D.Sc, F.R.S., 

 Director of the Rothamsted Experimental Station. Issued with the 

 authority of the Lawes Agricultural Trust Committee. [Pp. xl + 332, 

 with 49 figures and 101 tables.] (London: John Murray, 1917. Price 

 10s. 6d. net.) 



The first edition of this book, published in 1905, was essentially an account of the 

 experiments initiated and organised at Rothamsted by Sir John Lawes and Sir 

 Joseph Gilbert, whose remarkable collaboration, lasting fifty-seven years, not only 

 laid the foundation, but erected the superstructure of scientific agricultural in- 



