112 
Mycologia 
Another bulletin on “ Citrus Canker,” by H. E. Stevens, has 
been published by the Agricultural Experiment Station of the 
University of Florida. This bacterial disease, caused by Pseudo- 
monas Citri Hasse, has proved to be the worst plant disease that 
has appeared in Florida and seriously threatens the citrus industry 
of the state, as well as of the entire South. It affects all parts of 
the tree above ground and attacks most of the varieties of Citrus 
grown in Florida. The bacteria are capable of considerable desic- 
cation and retain their vitality for long periods. The complete 
destruction of all infected trees is the only known effective method 
of checking the spread of the disease, and this must be done very 
promptly if it is to be successful. 
The February number of Phytopathology, which is both large 
and attractive, contains a long list of important articles and also 
abstracts of all the papers presented at the Seventh Annual Meet- 
ing of the American Phytopathological Society at Columbus, Ohio, 
December 28-31, 1915. Among the articles, the following may 
be mentioned : “ Mordecai Cubitt Cooke,” by H. T. Giissow, “ The 
leaf blotch disease of horse-chestnut,” by V. B. Stewart, “ Some 
bark diseases of citrus trees in Florida,” by J. G. Grossenbacher, 
“ International phytopathology,” by Otto Appel, “ Identity of 
Peridermium montanum with Peridermium acicolum,” by George 
Grant Hedgcock, and “ The control of experimental conditions in 
phytopathological research,” by Alden A. Potter. 
An article on the discovery of the chestnut canker {Endothia 
parasitica) in Japan by Mr. Frank N. Meyer appeared in Science, 
February 4, 1916, contributed by C. L. Shear and Neil E. Stevens. 
About two years ago, Mr. Meyer discovered the chestnut canker 
in China. In a letter dated September 20, 1915, Mr. Meyer 
stated that the chestnut canker was quite common in Japan, at 
least around Nikko, Tokio, and Yokohama, both wild and culti- 
vated trees being attacked but showing considerable power of 
resistance. Mr. Meyer sent some of his collections to Dr. Shear, 
who found them to be absolutely identical with material collected 
in the United States on the wild chestnut tree. On January 8, 
