FUNGI AND FUNGOUS DISEASES OF PLANTS 243 
structures of the plant (fig. 188). Most of the damage is done 
to the fruit before any of these cups appear; indeed, the fruit 
is worthless before the parasite has matured. Spores are dis- 
tributed from the cups and new infection of fruit occurs, and 
thus the destruction is continued. The spores are formed 
within the tissues of the cup in the enlarged ends of hyphae, 
and these enlarged spore-forming tips of the hyphe are the 
sacs from which the group name sae fungi is derived. The 
sac is called the ascus (sac), and the group of plants is called 
the Ascomycetes (sac fungi). 
Brown rot seems to attack 
all kinds of stone fruits, and 
the total amount of damage 
done by it is enormous. In 
1887 it was reported that 
the disease had caused a 
shortage of 800,000 baskets 
in the peach crop of Mary- 
land and Delaware for that 
year. In 1900 Georgia lost 
about 40 per cent of its peach 
crop—a money loss of between Fic. 189. A group of morel mushrooms 
$500,000 and $700,000.21 
The disease may be checked by destroying the infected fruits 
and twigs. Spores are so generally distributed that spraying is 
also necessary. Different sprays have been used, but with such 
varying success that the advice of local experiment stations 
should be sought for the special needs in each state. 
231. The morel. Another representative of the sac fungi 
is the morel mushroom (Morchella) (fig. 189). Its mycelium 
grows in earth that is very rich with decaying organic matter. 
It is usually found in woods, among the leaves and about old 
logs and stumps. The mushroom is the only part usually 
noticed, and under favorable conditions of moisture and 
1‘ The Brown Rot of Peaches, Plums, and Other Fruits,’’ Bulletin 50, 
Georgia Agr. Exp. Sta., 1900. 
