THE CHESTNUT DISEASE (ENDOTHIA PARASITICA) 
other Grasses. 
371 
The ascospores affect the ovaries in early summer. 
In the ovary the mycelium develops, using the food material 
which the ovary should have. 
surface of the ovary numer- 
ous conidiophores which 
produce conidia abundantly, 
and the conidia are dis- 
seminated largely by insects 
which seek the honey dew 
secreted by the mycelium. 
After the tissues of the 
ovary are destroyed, the 
mycelium becomes trans- 
formed into a dark, hard, 
club-shaped body called 
sclerottum which projects 
from the spikelet as shown 
in Figure 821. These 
bodies, which are the so- 
called Ergot, contain one or 
more alkaloids which are 
poisonous to both man and 
live stock. Stock are some- 
times badly poisoned by 
eating Timothy, Red Top, 
and other kinds of hay 
where Ergot is abundant. 
The sclerotia fall to the 
ground and pass the winter. 
The next spring they de- 
velop branches which bear 
rose-colored globular heads, 
called stromata, in which the 
asci are produced in sunken 
perithecia. 
The mycelium produces on the 
Fic. 321. — The Ergot Fungus, Clavi- 
ceps purpurea. a, head of Rye, showing 
projecting sclerotia; b, a sclerotium which 
has developed stalks bearing globular 
heads in which the perithecia occur (X 3); 
c, section through one of the globular 
heads, showing the perithecia (X 15); d, 
ascus highly magnified, showing the 
spindle-shaped ascospores; e, hypha and 
conidia which develop on the surface of 
the grain in the early stage of infection. 
From Tulasne and Strasburger. 
The Chestnut Disease (Endothia parasitica). — This disease 
was introduced from Asia and appeared in New York about 
1904. 
It is very destructive to Chestnut trees, and the estimated 
loss in New York City and vicinity is more than $5,000,000. 
For the entire United States, the financial loss up to 1911 was 
