76 Nebraska Agric7iltural Exp. Station, Research Bui. 12 
DESCRIPTION OF PLATE IV 
A. Canker measuring 1 x 7 inches which developed within a 
single week. Stromata appeared on the surface during the same 
season. 
B. Portion of an older canker. No ascospores have yet been 
produced. 
C. Portion of a canker more than four years old. Much of the 
bark has fallen away but the stromata are still firmly attached. The 
black color is due to the presence of ascospores which have recently 
matured and been forced to the surface. 
D. Portion of an old canker with the stromata covered with 
conidia. 
E. Portion of a cankered limb from which the diseased bark has 
been cut away revealing the light colored spots with black edges wnere 
the stromata had been attached. 
