REVIEWS 321 



-until 1912 tliat lumber prices had reached the level of 1907, and then, because of 

 the slight business depression in 1914 and 1915, prices again broke sharply. The 

 general upward trend of prices, which began as early as the fall of 1915, did not 

 permanently influence lumber prices until the fall of 1916. The rise in lumber 

 that has taken place since has been greatly stimulated by Government orders and 

 the enforced curtailment of production on account of the labor shortage. In 

 ■spite of these aids lumber prices have not risen quite so much as the average 

 prices of 'all commodities.' " 



W. N. M. 



Manual of Tree Diseases. By W. Howard Rankin. The ]\Iacmillan 

 Co., New York. 191 8. Pp. 398. , 



This first wholly American work in book form on the diseases of 

 forest trees is one of "The Rural Manuals'' edited by Prof. L. H. 

 Bailey, and in conformity with the general plan of this series has been 

 written primarily for the general public. Insect and other animal in- 

 juries are not included. The treatment of the subject throughout is 

 simple and direct; the diseases are concisely described and methods of 

 control indicated. The first four chapters deal with such maladies of 

 biotic and abiotic origin as are common to many kinds of trees and are 

 respectively entitled "Seedling Diseases and Injuries," "Leaf Diseases 

 and Injuries,"' "Body and Branch Diseases and Injuries," "Root Dis- 

 eases and Injuries." Chapters \" to XXXII are devoted to an account 

 of the more "specific diseases," one chapter to each generic host group, 

 beginning w'ith the alders. The arrangement of the chapters is alpha- 

 betical, according to the English host group names. Two chapters 

 follow — one on "Tree Surgery," the other on "Spraying and Dusting 

 for Leaf Diseases." The book is equipped with a glossary, a general 

 bibliography of tree diseases, and an excellent index. 



This work, though not intended as a text-book, will be welcomed by 

 all students of plant pathology, because it is the only summary avail- 

 able of the diseases of the forest trees of the L'nited States and Canada 

 and because it includes many classified references to the literature. 

 The writing of the book reveals the limitations of forest pathology in 

 America ; the number of workers in this field has been small, the sub- 

 ject-matter is as yet largely unexplored, and the applications of the 

 results so far attained have been restricted. The author clearly recog- 

 nizes these facts and does not fail to point out the direction investiga- 

 tions should follow ; in so doing he makes a contribution of prime 

 importance. 



T. H. F. 



