464 Scientific Intelligence, 



to the Chlorophycege (or green algee). The 51 plates illustrate 

 every species and variety observed and are to be commended for 

 their accuracy and beauty. Several of the forms are here figured 

 for the first time, but even where earlier figures have been pub- 

 lished these have often appeared in scattered papers difficult of 

 access. It is therefore a great satisfaction to have these new 

 figures gathered together in a single work. a. w. e. 



7. An Introduction to Bacterial Diseases in Plants; by Erwin 

 F. Smith. Pp. xxx, 688, with frontispiece and 453 illustrations. 

 Philadelphia and london, 1920 (W. B. Saunders Company). — 

 The rapid advances made in the important field of bacterial plant 

 diseases are intimatel}^ associated with the investigations of 

 Dr. Smith. The present volume will therefore be most welcome, 

 not only to plant pathologists but to botanists in general. The 

 material presented is divided into five parts. The first deals 

 with the more general features of bacterial diseases, the following 

 subjects being among those discussed: distribution among the 

 families of flowering plants, period of greatest susceptibility, 

 method of infection, morpliologieal and cultural features of the 

 bacteria, reactions of the host plant. The second part takes up 

 in detail the methods of research. The third, which occupies 340 

 pages, gives full descriptions of fourteen important bacterial 

 diseases of economic plants, each being accompanied by references 

 to the literature. The fourth part suggests subjects for special 

 study, discusses the formation of tamors in plants, and gives an 

 account of teratosis in the absence of both tumors and parasites, 

 using for illustration the reinarkable Begonia phyUomaniaca. 

 The concluding part contains excellent advice to the botanist and 

 especially to the plant pathologist regarding research work and 

 matters pertaining to it either directly or indirectly. The book 

 is profusely illustrated, many of the figures being photomicro- 

 graphs of diseased plant tissues, reproduced by fine half tones. 



A. w. E. 



8. Text-hook of Pastoral and Agricultural Botany, for the 

 Study of the Injurious and Useful Plants of Country and Farm; 

 by John W. Harshberger Pp. xiii, 294, with 121 text-fignires. 

 Philadelphia, 1920 (P. Blakiston's Son & Co.).— For the past 

 twenty-five years the author has given a course in botany to a 

 class of veterinary students, and the present volume is based 

 upon this course. As might be expected some of the topics 

 treated do not find a place in the usual text-books of botany. 

 This is particularly true of the first nine chapters, in which 

 poisonous plants are discussed, not only from the standpoint of 

 their botanical features but also from the standpoint of the 

 various symptoms which they produce in poisoned animals. The 

 remaining chapters deal with important food plants, with soil- 

 nitrogen, with weeds, and with agricultural seeds. A full bibli- 

 ography is given at the close of each chapter, and directions for 

 laboratory work are interspersed throughout. a. w. e. 



