244 
Journal of Agricultural Research 
Vol. I, No. 3 
The sporophores when old and mature usually have a hard fibrous- 
corky to corky-woody context and a very rough, uneven, tuberculate 
upper surface, owing to the leaves, twigs, and other foreign substances 
falling on the upper surface of the growing pileus. (PI. XXII, fig. 4.) 
After weathering for some months, the color of the pileus is a chestnut 
brown or sometimes becomes almost black and rimose. The old spor¬ 
ophores as a rule are partially destroyed by insects, especially the sub- 
hymenial layer and the adjacent ends of the pores. Portions of the 
outer pore surface, the central part of the context, and the base of the 
sporophores usually persist and can be found attached to the bases of 
the diseased trees for several years after maturity. 
The mouths of the pores in the weathered sporophores are stuffed to 
a depth of 0.5 to 1 millimeter with a firm, brown mycelial mass, thus 
completely hiding all trace of the pores from a surface view. This stuffed 
pore layer becomes hard and brittle and gradually cracks in weathering 
and peels off from the deeper and more insect-eaten portion. Immature 
specimens shipped before being thoroughly desiccated have the tubes 
loosely stuffed with a delicate, white arachnoid mycelium, which appears 
on the spore surface as a thin creamy layer about 0.5 of a millimeter 
thick. This condition is probably due to a growth developed in the 
sporophore while in transit in a damp state. The stuffed mouths of the 
pores in old weathered sporophores is apparently a normal state of old 
specimens from certain sections of the United States. However, this 
stuffed condition of the pores in old sporophores is not always present, 
as several specimens both from America and Europe were seen by the 
writer in which the mouths were entirely free and open. 
The tubes in all the specimens examined—both American and Euro¬ 
pean—contain characteristic setse. They are dark chestnut brown, 
thick walled, curved, cat’s claw to hawk beaked in shape, giving them a 
somewhat bulbous-shaped base when seen in side view. They are 7 to 
12 pi thick at base, 15 to 24/jt long, and usually project 10 to 20 pt beyond 
the hymenial surface into the tube cavity. 
The sporophores vary greatly in shape and size, ranging from 9 cm. 
long, 5 cm. wide, and \% cm. thick to 20 cm. long, 15 cm. wide, and 10 
cm. thick, and may be simple or imbricated, depending to a great extent 
on the environment and food supply. In many of the thick sporophores 
growing from the collar of the tree the pore surface is borne at an angle 
of 40° to 6o° to a horizontal plane. In the thinner and broader speci¬ 
mens the pore surface approaches more nearly the normal angle of other 
dimidiate sporophores. The margin is very thick and rounded in most 
of the specimens. The cavities left in the upper surface of the pileus by 
the drops of water which exude during the rapidly growing period of 
the sporophore are plainly discernible even in many of the old sporo¬ 
phores. The pore surface extends entirely to the point of attachment 
to the substratum even when the sporophore has a rounded substipe, 
as is often the case when it forms on the upper surface of exposed roots. 
