230 Transactions British Mycological Society. 
*Coronophora angustata Fuck. in Fung. rhen. No. 1854. 
On beech, Lytchett Matravers, Dorset, April, 1922. This 
fungus is close to C. gregaria Fuck. but has much smaller spores. 
The peculiarities of the fructification of this species are described 
by Petrak in Ann. Myc. xix (1921), p. 182. He thinks the 
manner in which the asci are evolved affords support to the 
correctness of von Hohnel in creating a family Coronophoreae. 
BARK CANKER DISEASE OF APPLE TREES 
CAUSED BY MYXOSPORIUM CORTI- 
COLUM EDGERT. 
With Plates IX—XI and 3 Diagrams in text. 
By Grace G. Gilchrist, B.Sc. 
INTRODUCTION. 
At Long Ashton in 1920, a disease was noticed in a plantation 
of bush apple trees doing very severe damage to the branches. 
In some cases, only one branch was affected, in others four or 
five branches were attacked and in others the disease had reached 
the crown of the main trunk and the trees were doomed. A char- 
acter of the disease was the formation of large longitudinal scars 
on the sides of the branches and this symptom, together with 
the occurrence of numerous pustules of spores of the fungus 
Myxosporium corticolum Edgert., led to the identification of the 
disease as bark canker. Hitherto this disease had not been 
reported in this country although it has been known in the 
United States for some years. 
HISTORICAL NOTES. 
In 1908 Edgerton(:) briefly described the bark canker as 
being produced by a new species of Myxosporium, which he 
named Myxosporium corticolum. He found the fungus to be 
perennial, living from year to year in the bark and forming a 
new ring of growth each year. The description which he gives 
of the appearance of the disease agrees closely with the symptoms 
observed at Long Ashton and which are described in detail later. 
The spore pustules were small, about 1-2 mm. in diameter, 
slightly raised at the place where the bark was ruptured. The 
spores were observed to ooze out of the pustules in white 
tendrils, but they readily separated in water. He described 
