CLASSIFICATION 407 



often form irregular crusts, or spread in nodulose masses over 

 various substances. Some are whitish in colour, others brownish 

 or purplish. 



CORTICIUM 



Forming broadly effused, completely adnate crusts on wood and 

 bark, or very rarely with the extreme edge free. Hymenium waxy, 

 smooth, even, usually presenting a polished appearance, becoming 

 cracked when dry, due to contraction. The uneven or nodulose 

 appearance sometimes met with is due to the fungus following 

 closely the irregularities of the matrix upon which it is growing. 

 Somewhat difficult to separate from species of Stereum. In the 

 last-named genus, however, some portion is usually free from the 

 substratum or matrix, and the upper or sterile surface of such free 

 portion is always densely ^^elvety or strigose ; and, further, the 

 hymenium in Stereum does not crack during drying. 



Peniophora 

 Forming large crusts or patches on wood, bark, which may be 

 entirely adnate or attached to the matrix throughout, or one edge 

 may be free and spreading away from the matrix. The hymenium 

 is even, but when examined under a good pocket lens is seen to te 

 densely covered with minute colourless bristles, which are in reality 

 the projecting points of the hymenial structures called cystidia. 

 The presence of these projecting cystidia is practically the only 

 distinction between the present genus and Corticimn. To under- 

 stand cystidia properly, a thin section of the hymenium should be 

 examined under the microscope. 



Hymenoch.ete 

 Forming dry, coriaceous patches, either entirely adnate or partly 

 free and reflexed or bent away from the matrix. The hymenium, 

 when examined with a pocket lens, appears to be minutely 

 bristly, due to the presence of myriads of projecting cystidia. But 

 in this instance the cystidia are coloured deep brown ; whereas in 

 Peniophora the cystidia are colourless. Microscopic examination 

 will reveal other points of distinction between the cystidia of the 

 two genera named. In Peniophora the cystidia are very thin- 

 walled, and near the tip encrusted with particles of lime. In 

 Hymenochcete the cystidia are very thick-walled, coloured, and 

 smooth. The hymenium is usually dark rusty brown or orange- 

 brown, the margin sometimes deep yellow or orange. 



Stereum 

 In the higher species the habit simulates that of the most perfect 

 forms of Thelepiiora. The stem is central, supporting a more or 

 less funnel-shaped cap, which is more or less lobed or incised at the 



