102 HEART-ROT 
made very nearly up to the margin, so that in the resting 
stage the fungus has the appearance shown in fig. 39. 
A very constant feature of the fructifications of this 
species is the holes in the sporophores. When the latter 
encounter a small root or stick, or even a blade of grass, 
they grow round it, leaving a hole such as those seen in 
fig. 39. These holes differ from those made under similar 
circumstances by most other fungi, by being surrounded by 
a reddish-brown ridge of sterile 
tissue. This ridge forms one 
of the most useful features for 
identification. Fig. 39 shows 
the appearance of the lower 
surface of the pores. It will 
be seen that they vary from 
circular to irregularly oval or 
elliptical. Their width is 
usually about 0-25 mm. 
(= ro0in.), but may be any- 
Fic. Tie annosus: A, thing from 0-15 to 0-6 mm. 
hymonial ayer ise poe: 8 The pores axe not. fori 
b., older basidium with four spores; through their whole length at 
py araphyss (200); 3; Si8I6 ho same time. As a, fructi- 
dium ; 0., basidium ; st., sterigma; fication grows older the upper 
saggeutams sp baidogpors( part of each pore becomes 
filled with hyphac, and only 
.the lowermost 1 to 2 cm.,i.c. the part nearest the openings, 
bears spores. During the summer the pores Jengthen and 
the fertile zone moves downwards. Fig. 38 shows the pores 
in longitudinal section ; two pieces of the fungus are here 
cut through, in each of which two years’ growth can be 
distinguished. 
In the fertile region cach pore is lined with the hymenium, 
a layer made up of Lasidia and paraphyses. Fig. 41, a, 
shows this layer as seen in a longitudinal section of the 
pores. The basidia are 30-40 long and 8-10, broad. 
Normally each bears four spores (b.), but basidia with two 
spores are frequent (a.), and basidia with three or five spores 
