436 



NATURE 



[March 13, 1890 



rolling-stock to the highest pitch ; his engines are patterns 

 to be used with advantage, and their coal consumption is 

 the lowest on record. Chapter IX. describes the South- 

 Eastern and Chatham Railways ; and the volume concludes 

 with Chapter X., on the Great Eastern Railway. These last 

 chapters lack none of the interest to be found in the 

 earlier ones in the book. 



The second volume, on Scottish railways, is merely a 

 continuation of the first, and is written in the same lucid 

 style. Its most interesting part is a description of the 

 Forth Bridge. Mr. Acworth gives a good account of the 

 bridge and the earlier schemes proposed for'crossing the 

 Forth. 



Mr. Acworth has written two most interesting books, 

 which will be of great use to all in any way connected 

 with, or interested in, the British railway system. 



N. J. L. 



DISEASES OF PLANTS. 



Diseases of Plants. By Prof. H. Marshall Ward, F.R.S., 

 M.A. (London : Society for Promoting Christian 

 Knowledge.) 



THIS little book is an excellent popular introduction 

 to the study of the diseases of plants, in so far as 

 they are due to the attacks of parasitic Fungi or similar 

 organisms. The author, who has inade this field of re- 

 search especially his own, succeeds in being intelligible 

 and interesting to ordinary readers, without in any degree 

 sacrificing the scientific character of his work. 



The book is illustrated by fifty-three woodcuts, which 

 have been very well selected, many of them from the 

 author's own papers. In certain cases, however, the 

 engraving leaves something to be desired, and scarcely 

 does justice to the original figures. 



An introductory chapter explains what is here meant 

 by disease in plants, namely " those disturbances of the 

 structure and functions of the plant, which actually 

 threaten the life of the plants, or at least their existence 

 as useful objects of culture." The two factors of disease? 

 the external cause on the one hand, and the condition of 

 the patient on the other, are clearly distinguished. 



The second chapter gives a general account of Fungi 

 as saprophytes and parasites. Mucor is described as an 

 example of the former, and vine-mildew {Peronospora 

 viticold) of the latter group. 



The succeeding nine chapters, forming the bulk of the 

 book, are occupied with the consideration of special 

 diseases. 



First comes the " dam ping-off " of seedlings, a disease 

 only too well known to gardeners, due to the attacks of 

 various species of Pythium. The whole life-history of 

 the parasite is described. In Fig. 9 it is a pity that the 

 point of attachment of the antheridium is not more 

 clearly shown. 



Next, we have an account of the very interesting 

 disease of cabbages and other Crucifers, known as 

 " fingers and toes," " club-root," &c. Here the cause of 

 the mischief is a Myxomycete, and this is the only case 

 of a non-fungoid disease described in the book. Happily, 

 a satisfactory cure can here be prescribed. 



Chap. V. is on the potato-disease. An account of the 

 normal mode of nutrition of the plant in health is in- 

 troduced in order to show the exact nature of the 

 deadly injury which is wrought by the Phytophthora. 

 As a preventive measure, the selection of resistant 

 varieties of the potato is especially recommended. 

 Chap. vi. is devoted to the " smut " of corn. The 

 cause of the frequent failure of protective dressings 

 applied to the ripe grain is discussed. If, however, as 

 Jensen believes, the ovule may be infected at the time of 

 flowering, an altogether new light is thrown on this 

 question. 



After a chapter on the disease known as " bladder- 

 plums," caused by the yeast-like Fungus Exoascus, we 

 come to the lily-disease. The Fungus which is here 

 responsible has been shown by Prof. Ward to afford an 

 excellent example of a saprophyte which can become a 

 parasite on occasion. 



The next three chapters describe the ergot of rye, the 

 mildew of hop (Podosphaera), and the rust of wheat. In 

 the case of the hop-disease, a figure of the conidia might 

 have been added with advantage. The now familiar but 

 always interesting story of the hetercecism of rust is 

 well told. 



With a caution which in the case of a popular work 

 cannot be too highly commended, the author avoids 

 expressing any opinion on the subjects of fertilization in 

 Podosphasra, and of the function of the spermogonia in 

 ^cidium. 



In the concluding chapter, Prof. Ward endeavours to 

 interest his readers in the wider questions of mycology, 

 so fascinating to the botanist, such as the phylogenetic 

 origin and relationships of the Fungi. 



The book should have a wide circulation among the 

 numerous classes interested in the important group of 

 diseases of plants with which it deals. 



D. H. S. 



OUR BOOK SHELF. 



The Physicia7i as Naturalist. Addresses and Memoirs 



bearing on the History of and Progress of Medicine 



chiefly during the last hundred years. By W. T. 



Gairdner, M.D. (Glasgow : Maclehose and Sons^ 



1889.) 



A SUCCESSFUL physician, during a long and busy life, is 



frequently called upon to preside and deliver addresses 



at meetings at which he is expected to treat his subjects 



in a more or less popular manner. 



Dr. Gairdner has brought together a most interesting 

 series of such addresses, which fall into two main groups. 

 First, those in which he has contrasted the treatment 

 of the present day with that in vogue among our pre- 

 decessors of more or less remote times ; and in which 

 he has attempted to present the answer to that ever- 

 interesting question, " Is the treatment of disease 

 adopted at the present day superior to that in vogue 

 formerly ? And if so, in what does its superiority consist .? '^ 

 Second, those in which he lays down the lines on 

 which he considers the medical education of the future 

 should be conducted, in order to lead to still greater 

 advances. 



The dependence of modern treatment upon the dis- 

 cussion of accumulations of facts, and not solely upon 

 theory, and the necessity of making experience and 



