FUNGUS DISEASES 
203 
interest, particularly in the case of Cephaleuros , Thread Blights, and 
the characteristics of diseased roots when attacked by different fungi. 
The illustrations are very good and the coloured plates of leaf 
diseases, stem and root diseases, and root diseases, respectively, are 
excellent in every way, except that some of the greens do not come 
out well. An extensive bibliography and a full index complete a 
work which will be invaluable not only to planters, hut also to those 
mycologists who are concerned with tropical phytopathology. 
(2) The “Report on the Occurrence of Fungus, bacterial and allied 
Diseases on Crops in England and Wales for the Years 1920-21 ” 
is a summary of the original pathological returns received by the 
Ministry. Owing to the somewhat perplexing move of the Plant 
Disease Branch of the Ministry from Kew to Harpenden, the Report 
for 1920 was so delayed that it was found advisable to issue it 
together with that of the following year. Fortunately there was a 
very great dissimilarity between the two seasons, the summer of 
1920 being unusually cold and wet, whereas that of 1921 was excep¬ 
tionally long and warm; and this difference is reflected in the inci¬ 
dence of certain diseases. Such annual surveys of the occurrence of 
plant disease have been found useful in many countries, and have an 
additional use in comparative international phytopathology. In the 
present work the diseases are listed under the general headings 
Cereals, Potatoes, Roots, Pulse, Forage Crops, Vegetables, Fruit, and 
Miscellaneous. A popular name is given for the disease together 
with its scientific name : the points of its special occurrence in the 
last two years are noted, with recent relevant results obtained in the 
investigation of the disease either in this country or in other British¬ 
speaking countries—references to continental work are very infrequent. 
A further useful point is that information is given when it is known 
that a disease is under investigation in this country. The survey will 
be extremely useful to phytopathologists. Naturally it suffers, as 
must all such lists, in that the data are supplied by people with dif¬ 
ferent interests, opportunities, and efficiencies ; in connection with this 
no authority is given for the naming of the fungi concerned. In the 
case of the more important diseases this is of little importance, as we 
may assume that the fungi are well known ; but for rarer species it 
would have been well to indicate the persons responsible for the 
identifications. In a pocket in the cover are two weather charts 
which are useful in studying the relation of weather conditions to the 
reported incidence of diseases during the two years. 
A foreword gives the information that the report has been pre¬ 
pared by Mr. A. D. Cotton, lately Mycologist to the Ministry ; and 
adds—“ It is a matter of regret that his connexion with the Patho¬ 
logical laboratory has now been severed by his acceptance of the post 
of Keeper of the Herbarium at the Royal Botanic Gardens, Kew.” 
J. R. 
