6 BULLETIN 684, U. S. DEPARTMENT OF AGRICULTURE. 
year the fungus is usually to be found. However, neither furnished 
a good medium for the fungus, and as a result the number of spores 
(usually conidia) produced is quite small compared with the number 
which the fungus produces when growing in a newly rotted fruit of 
the current season. The size of the spores is usually somewhat re- 
duced also. ‘ 
A mummy hanging on a tree furnishes a medium which is de- 
ficient in moisture and in plant food. In the case of the rotted 
apples on the ground the bitter-rot fungus must compete with many 
of the mold and rot fungi and bacteria which are less susceptible 
to cold and which are true saprophytes. In examining rotted fruits, ~ 
one finds a mixture of the spores of the bitter-rot fungus and those 
of various molds, together with numerous bacteria. 
In both Virginia and Arkansas orchards, mummies and rotted 
fruits undoubtedly are important sources of infection. The writer 
has examined infected orchards in Arkansas in which bitter-rot  « 
mummies and rotted fruits of the preceding year were abundant in _ 
the trees and on the ground and in which no other sources of in- 
fection could be found. Some of the most seriously infected or- 
chards which the writer has seen, however, were Arkansas orchards 
from which the mummies and rotted fruit had been removed. Gen- 
erally, in Arkansas few mummies are to be found in the trees, and 
as nearly all growers practice clean cultivation throughout the 
earlier part of the season those which have fallen to the ground 
have been turned under. It has been a common practice, too, for 
the grower to gather up and haul to evaporating plants the best of 
the dropped fruit and to sell the rotten and diseased fruit to the 
distilleries. 
The writer agrees with Alwood and Scott that mummies are the 
chief sources of infection in the orchards of Virginia. In that State 
the Yellow Newtown variety, known locally as the Albemarle Pip- 
pin, is the commercial variety which is damaged to the greatest 
extent by the disease. This variety is grown for the most part in 
coves of the Blue Ridge, situations which usually do not admit of 
cultivation. These trees do not come into bearing until they are 
about 15 years old, and they are very long lived. Accordingly, most 
of them are rather old and quite large. The dropped fruits 
have no economic value. There are many reasons, therefore, why 
rotted fruits should be left on the ground. There are usually some 
mummies also to be found hanging on trees of such size. The writer 
counted more than a hundred on one tree, which, however, was an 
unusual number. In Virginia he was easily able to trace the source 
of clumps of rotted fruits to mummies hanging in the trees. This 
is readily done if examination is made shortly after the first out- 
break of the disease. 
