114 College of Forestry 
resses the hyphe quickly ramify and penetrate adjoining 
cells, soon extending in all directions throughout the woody 
tissue. They are comparatively small, rarely being over two 
microns wide, usually much less. Cross-walls and clamp 
connections are occasionally discernible in the larger hyphee. 
Careful examination was made of sections of decayed wood 
to determine the action of the fungal hyphze on the erystals 
of calcium oxalate in the wood parenchyma cells. In no case 
could any solvent action be noted. In a nwiber of instances, 
however, crystals were seen which remained intact after all 
the surrounding woody tissue had been completely dissolved 
away. The crystals, of course, were retained in their original 
position in the sections by the celloidin matrix in which the 
material was imbedded. It would seem from this circum- 
stance that these crystals are not only of no use to the fungal 
hyphe but are not capable of being reduced by their enzyme 
secretions. 
As in the decay of sugar maple wood, longitudinal sections 
of decayed wood showed a matting of fungal hyphee within 
the vessels, these hyphee often being encrusted with brown 
decomposition products. Sections (taken near the black 
zones) of wood in the early stages of decay exhibited abun- 
dant brown gum-like masses of decomposition products 
occluding the lumina of the vessels and other elements. 
Ture Decay or CuEestnutr Oak Woop. 
Structure of the Normal Wood.— The wood of the chest- 
nut oak (Quercus prinus Linn.) is heavy, hard, strong, tough, 
moderately close-grained, and durable in contact with the 
soil. The heartwood is yellowish or reddish brown and 
sharply defined from the lighter and slightly reddish, narrow 
sapwood. 
Macroscopically the wood of chestnut oak presents the 
usual features of the ring-porous type, the pores abruptly 
diminishing in size from early to late wood. The larger 
pores contain abundant tyloses. The pores in the early wood 
are arranged in 8—5 rows and are conspicuously large; those 
in the late wood are minute and arranged in. radial lnes 
