PLANT DISEASES 149 



It is easy to find fault with a work like the present ; but we 

 welcome it as a much-needed stimulant to the current of thought 

 in a direction where too much is apt to be taken for granted ; and 

 it reflects throughout the close study, the considerable experience, 

 and the keen interest of the writer. 



H. F. Wernham. 



Plant Diseases. 



1. Grundzilge der Allgemeinen Phytopathologie. By Professor Dr. 



H. Klebahn. Berlin : Gebriider Borntraeger. 1912. Pp. 

 147. 74 figs. Price 4 mk. 80 pfg. 



The science of Plant Pathology which deals with conditions 

 and organisms hurtful to plant life has received ever increasing 

 attention in recent years. So many facts and observations 

 concerning the causes of arrested growth or premature decay 

 in the vegetable kingdom have been tabulated, that a stage has 

 been reached when it seems not only possible, but highly 

 desirable, to make a general survey — to take stock of the addi- 

 tions to our knowledge in this field of research. Dr. Klebahn's 

 work on the characteristic features of Phytopathology provides us 

 with just such a general consideration of the subject. Under 

 "causes of disease" he enumerates chemical, physical, and 

 climatic conditions, wounds and attacks by parasitic organisms — 

 plant and animal. He also includes the more obscure disturb- 

 ances in the metabolism of the plant, and diseases of which the 

 origin or cause is unknown. 



As Dr. Klebahn points out, it is very rarely that disease can 

 be traced to any single one of the causes given. Usually it is the 

 interaction of a series of adverse conditions. Poverty of the 

 soil, for instance, may so affect the vitality of the plant that it 

 succumbs easily to cold or drought, or falls a ready prey to 

 parasitic attacks. 



The author deals in this treatise with broad principles, leaving 

 aside the detailed account of particular cases of disease, and he 

 winds up with a chapter on teratology, abnormalities and varia- 

 tions, the origin of which is doubtful. They are not generally 

 reckoned as diseases, but they may cause serious disfigurement. 

 His book will be welcomed by students as a helpful and suggestive 

 contribution to the science of Plant Diseases. It includes a 

 bibliography of 269 citations, and a copious index, and is illus- 

 trated by figures in the text which are clear and good. 



A. L. S. 



2. Plant Diseases. By Dr. W. F. Bruck, translated by J. E. 



Ainsworth-Davis. Blackie & Son, Ltd. 1912. Price 2s. 



net. Pp. 152. Illustrated. 



This attractive-looking little book is a translation of Brack's 



Pflanzen-Krankheiten in the well-known Sammlung Goschen 



series. It is the best short introduction to the study of plant 



diseases that we know, but we should have thought that one of 



