10 BULLETIN 871, U. S. DEPARTMENT OF AGRICULTURE. 
persist in a dead fallen tree it is impossible to state, but the last 
figure given indicates a rather extended period in some cases. These 
cases refute the statements of Harkness (7) and Yon Schrenk (26, 
p. 75) that the mycelium does not grow after the death of the tree. 
On dead down trees the sporophores were never half bell shaped or 
ungulate, but were more typically near the subapplanate type. 
Since so few cases of sporophores on dead fallen trees have been 
recorded during a rather extended period, it is safe to assume that 
infected fallen trunks are of slight importance from the standpoint 
of forest sanitation in infecting living trees through the production 
of sporophores. 
Although sporophores are rather rare, an accurate indication of 
the place formerly occupied by a sporophore is supplied by the 
shot-hole cup (PL II), so termed and described by Meinecke (15, 
p. 23, 46). These shot-hole cups appear as cup-shaped depressions 
below a knot, the depression being riddled with numerous fine holes. 
At first they have the color of the freshly opened bark of the tree, 
but later become weathered and gray with age. They are formed 
in the following manner: The soft fleshly or cheesy sporophores 
issuing through knots are usually soon eaten by squirrels and micro- 
lepidopterous larvae. Some of these larvae then bore into the bark 
of the tree, where they are sought after by woodpeckers, which 
chop out a cup-shaped depression in the bark, corresponding to the 
place formerly occupied, by the sporophores. This depression is 
riddled with what appear to be numerous fine shot holes, the burrows 
of the insect larvae. 
The presence of a shot-hole cup is just as reliable an index of dry- 
rot in a tree as is a sporophore. However, the same diagnostic 
values in relation to the age of the fungus plant in the tree, and 
consequently the extent of the resulting decay, must not be attached 
alike to sporophores and fresh and old shot-hole cups. An old, 
gray, weathered shot-hole cup would indicate the most extensive 
serious decay, while a fresh shot-hole cup, in turn, would indicate 
more extensive decay than a sporophore, since it is evident that 
more time must elapse before a shot-hole cup is formed than a sporo- 
phore and the longer the fungus plant lives in the heartwood the 
greater the amount of decay resulting. 
The number of sporophores occurring on a standing living tree is 
typically one. Yon Schrenk (27, p. 205) gives the number as 
usually one, but it must be remembered that at this time no descrip- 
tion of Polyporus amarus had appeared, so it can not be stated 
definitely that Yon Schrenk was referring to this fungus. However, 
Meinecke (15, p. 46, pi. 12) gives the number as typically one. Some- 
times two have been found. As many as five shot-hole cups have 
been observed on a single living tree, but an examination of their con- 
