BOOK REVIEWS. 



603 



will render recognition unusually simple. But this is not all, for the 

 life-history of each tree, from the seedling to the matured timber, 

 has been carefully worked out, and in a remarkably interesting and 

 accurate way. 



We can confidently recommend the book to all who take an 

 interest in the history and development of our commonly cultivated 

 trees and shrubs. 



" Trees in Winter, their Study, Planting, Care, and Identification." 

 By A. F. Blakeslee, Ph.D., and C. D. Jarvis, Ph.D. 8vo., 446 pp. 

 (Macmillan, New York and London, 1913.) 8s. 6d. net. 



The title, unfortunately, gives but a partial idea of the scope and 

 usefulness of this book, which in reaUty is an excellent resume of the 

 propagation, planting, and general care of trees — their study and 

 identification being also well attended to. Even the enemies of trees 

 have received attention in the matter of insect and fungus pests, with 

 the best means of eradication ; while injuries brought about by gas 

 fumes, neglected pruning, and from various other causes, are all dealt 

 with. 



The illustrations, too, are numerous and well executed, and will 

 greatly aid the text. Though American methods connected with 

 tree management are somewhat different from what is considered 

 orthodox in this country, yet the advice is sound, and such chapters 

 as those devoted to planting, pruning, and selection of trees for special 

 purposes are of great value, and contain a large amount of useful 

 information to the planter. 



There is an excellent chapter on town planting, from which much 

 may be learnt regarding the management of trees in our public 

 streets and squares, and also the accidents and diseases to which trees 

 so situated are liable. The identification of trees both from illustra- 

 tions and letterpress leaves little to be desired, while taken as a whole 

 the work will be a distinctly useful one, and is to be recommended. 



"Cocoa." By Dr. C. J. J. van Hall, Director of the Institute for 

 Plant Diseases and Cultures, Buitenzorg, Java. 8vo. xvi + 5^5 PP- 

 With illustrations and map. (Macmillan, London, 1914.) 145. net. 



The cultivation of cocoa has become such an important industry 

 of recent years, especially in some of the colonies within the British 

 Empire, that a comprehensive work on the subject by such a com- 

 petent authority as Dr. van Hall is particularly welcome. Although 

 the existence of the cocoa plant was known in Europe in the early part 

 of the sixteenth century, and its products were introduced into Spain in 

 the latter part of the same century, it was not till after 1828, when van 

 Houten had discovered a method of making cocoa powder by eliminat- 

 ing most of the fat or cocoa-butter from the seeds, that cocoa came 

 into general use as a beverage. This is illustrated by the fact that in 

 1822 the consumption of cocoa in England was only 523,0001b., whilst 

 in 1909 it was 88,133,000 lb. 



