June, 1955 
that the material was kept in the iced pic- 
nic boxes between the point of collection 
and treatment in the laboratory never ex- 
ceeded 5 days. 
Mats were sampled on the trees in the 
following manner. After a mat had been 
| Glass ry F 
Curt: Oak Witt INocuLA 
283 
located, a square or rectangular area ex- 
tending slightly beyond the outer limit of 
the mat was marked off by driving a sharp 
chisel through the bark. The bark was 
then lifted easily and cleanly from the 
wood, and the mat beneath was exposed. 
Fig. 3.—Mycelial mats of Endoconidiophora fagacearum representative of condition classes 
arbitrarily established on the basis of mat development and decline: class I, immature; class 
II, mature; class III, aging; class IV, declining; class V, deteriorating. 
