It is very disturbing to find that three of the first four European 
oaks exposed to blight are somewhat susceptible, as the implica- 
tions are that other species will be found susceptible. 
E. SYMPTOMS OF THE BLIGHT 
15. ‘The first apparent symptom of the blight on chestnut is the 
dying of a limb or a part of the tree. Sometimes the entire tree may 
be affected. During the growing season, the leaves of the affected 
part turn yellow and brown and usually hang on tenaciously. If the 
killing of the part takes place during the late fall or winter, the 
affected part, or the intire tree, may not leaf out in the spring. The 
girdling or death of the part is brought about by the growth of the 
blight fungus in the bark and outer layers of the wood. If one cuts 
into an infected area, he will note fans of buff to whitish mycelium 
in the bark. These fans of mycelium are very characteristic of the 
chestnut blight fungus and are helpful in distinguishing blight from 
other causes of death. On the surface of the bark, there are produced 
small reddish-bronze fruiting bodies, usually about the size of a 
pinhead. Two forms of spores are produced in these fruiting bodies. 
16. One characteristic feature of blight |infections on chestnut 
is the abundant sprouts that usually are present below a girdled 
canker or when the entire tree is killed at ground level. 
At. A number of European countnies have published circulars or 
bulletins describing blight, and these can be referred to for more 
detailed description of the disease. 
Symptoms of blight on oaks are discussed on page 12. 
F. DISTINGUISHING CHESTNUT BLIGHT FROM INK DISEASE 
18, Over 100 years ago a destructive introduced root disease 
was reported as causing losses of chestnut in Portugal and Spain. 
Now this disease, known as the ink disease, has spread through 
many parts of the chestnut growth in the Mediterranean countries ; 
in the last 50 years, in many areas, it has killed a large proportion 
of the chestnut trees, particularly those growing at the lower eleva- 
tions. It is caused by two fungi, Phytophthora cinnamomi and 
P, cambivora, which kill the roots. I examined stands of trees in- 
fected with this ink disease in a number of countries and noted 
that actual damage now being caused is small as compared with 
the destruction being caused by chestnut blight in Italy. 
13 
