180 THE PLANT WORLD 



BOOK REVIEWS. 



Disease in Plants. By H. Marsliall Ward, Sc. D., F. E. S. 309 pages. 



Macmillan & Co., New York and London, 1901, 



In tlie above work we have a fresh and interesting general discus- 

 sion of this subject. The book is one of a set termed "Nature Series." 

 In the treatment of the subject the author has departed somewhat from 

 the usual method of presentation. The book is divided into two parts, 

 the first of which, "Some Factors," is scarcely covered by the title of 

 the work. This consists of eight chapters devoted to a concise and 

 very readable account of the present status of our knowledge of the 

 principal facts of plant physiology, i)ointing out the great advances 

 which have recently been made in our knowledge of this subject. Part 

 2, " Disease in Plants," includes chapters IX to XXX. In the first 

 chapter of this part are given brief but comprehensive discussions of 

 phj^topathology and the most important steps in its developments with 

 its divisions. In the next chapter we have a discussion of health and 

 disease, in which is pointed out the difliculty of giving an exact defini- 

 nition of disease and of deciding when disease is present in a plant. 

 In the next chapter on " Causes of Disease," attention is called to the 

 great number of factors which influence the plant, and the difliculty of 

 deciding to which the disease is attributable. The living and non- 

 living environments with their complex interactions make it very difli- 

 cult to determine the exact cause of any trouble. Tlie next chapter is 

 given to a discussion of the living environment in its relation to plant 

 diseases. Here brief discussions are given of injuries by man and other 

 animals, and also those which are either directly or indirectly caused 

 by plants. Next follow chapters on the nature of disease, spreading of 

 disease and epidemics, the factors of an epidemic, remedial measures, 

 variation and disease, symptoms of disease, artificial wounds, excres- 

 cences, exudations and rotting, necrotic diseases, monstrosities and 

 malformations, and finally one on life and death. The book is intended 

 for the use of practical agriculturalists and the gardeners, and treats of 

 the various subjects in a brief and non-technical manner, but at the 

 same time presenting the essential facts regarding the subject as they 

 are understood at present. The book should be carefully read by all 

 students taking up work in phytopathology. The author's scientific 

 standing as a phytopathologist is sufiicient guarantee for the accuracy 

 of the work, which should be ead by all who are interested in this 

 subject. — C. L. S. 



