SOURCES OF APPLE BITTER-ROT INFECTIONS. i 
In many Virginia orchards the lower Lmbs when laden with 
fruit reach to the ground. Im such cases the disease could be found 
first on the fruits in contact with those of the previous season on 
the ground. From these infected fruits spores could easily be car- 
ried to sound ones. 
The writer has frequently nbtenmpted to find the fungus in mum- 
mies and rotted fruits which were more than a year old, but has been 
uniformly unsuccessful. Those upon the trees appear to be dried up 
so thoroughly at the end of a year that they drop from the tree; 
those on the ground finally become almost wholly disintegrated 
through the action of molds and bacteria. 
In Virginia, therefore, mummies and rotted fruits, being more 
prevalent, are of more importance as sources of iNtection than they 
are in Missouri and Arkansas. In the last-named States cankers may 
overshadow them in importance. 
BITTER-ROT CANKERS. 
REVIEW OF THE LITERATURE. 
In 1902 R. A. Simpson discovered that in Illinois a certain type 
of canker was associated with outbreaks of bitter-rot. He found 
that if search was made shortly after the first outbreak of the dis- 
ease such cankers were to be found just above a clump of infected 
fruits. Simpson’s discovery was announced at about the same time 
by Burrill and Blair (4) and by Von Schrenk and Spaulding (13). 
Burrill and Blair (4) in 1902 stated that Hasselbring had shown 
the fungus found in these cankers to be identical with the bitter-rot 
fungus. Hasselbring found that the fungus from the cankers would 
cause typical bitter-rot when introduced into sound apples. 
Von Schrenk and Spaulding (18) in 1903 also showed that spores 
from the cankers could cause typical bitter-rot when introduced into 
sound apples. They further showed that spores could be washed 
from the cankers by water and that when falling upon apples they 
could produce bitter-rot. ‘To determine whether or not the Glomer- 
ella could actually be the causal organism involved in the production 
of cankers, they inoculated sound branches with spores (conidia) 
from pure cultures. As a result of these inoculations cankers were 
formed which showed the characters of the cankers found by Simp- 
son. From these artificial cankers Von Schrenk and Spaulding re- 
isolated the fungus and also inoculated apples with conidia produced 
in the cankers. They describe the development of the artificially pro- 
duced cankers as follows: 
Several weeks elapsed before there was any evidence of development on 
the limbs. In both the inoculated slits-and tne control slits the bark dried 
somewhat along the edges of the slit, making a gaping wound. After some 
