THE RECEPTACLE 



35 



woody, contains less moisture, and consequently dries with but 

 little shrinking or change of form. 



As the carpophore is sometimes obsolete in the JSymeno- 

 mycetes, so also is the receptacle or pileus reduced to a simple 

 stratum, which intervenes between the mycelium and the 

 spore -bearing surface. These are undoubtedly rudimentary 

 forms, but they are very numerous, sometimes constituting 

 entire genera, as in Poria, Coniophora, Corticium, etc., besides 

 numerous species in other genera. For the most part a thin 

 fibrous stratum, differentiated from the fibres of the mycelium, 

 forms, and supports the hymenium. Possibly the old genus 

 Ozonium consists entirely of these suppressed pilei, which never 

 form a hymenium. The supporting stratum is very peculiar 

 in Aster ostroma, where the hyphae are stellate, and in Thele- 

 pJiora pedicellata they assume a dendritic form. It is not 

 uncommon to find specimens of Corticium in which the 

 hymenium is only in patches, or, in some cases, never formed at 

 all, so that the whole Fungus remains in the vegetative stage, 

 that is to say, mycelium, and a sterile fibrous stratum to 

 represent suppressed carpophore and atrophied receptacle. 



The second type is deficient in any appreciable carpophore 

 or stem, and con- 

 sists of a pileus of 

 a semicircular out- 

 line, attached at its 

 base to the matrix 

 and its own my- 

 celium (Fig. 17). 

 In these also there 

 is a superior stra- 

 tum, which may be 

 thicker than in the 

 preceding, an inter- 

 mediate substance, 

 and an inferior hy- 

 menium. The upper 

 stratum in Folyporus and Fistulina is hardly distinct from 

 the intermediate ; but in Fomes it usually forms a firm 

 hard crust, very hard and horny in Fomes australis and 



Fig. 17. — Fistulina liepatka, sessile pileus. 



