394 



FUNGI 



The trama is that portion of the projection which bears the subhyme- 

 nial layer, and consists of hyphae running parallel to the surface from 

 the insertion of the projection to its margin, which in many cases is un- 

 covered by the hymenium. 



The hymenium itself consists of parallel rows of club-shaped basids 

 surmounted bysterigmata and basidiospores. The basids are the termi- 

 nations of the subhymenial hyphfe, but the latter also frequently end 

 in sterile cells, which are termed paraphyses, frorii the fact that they 

 stand in the same relation to the basids as the paraphyses do to asci. 

 Large inflated cells, often of relatively great dimensions, called cystids. 



Fig. 323. — Polyporus igniarlus Fr. Upper surface (half natural size). (After Luerssen.) 



are frequently found emerging from the hymenial surface (fig. 321). They 

 are very variable in form, club shaped, flask -shaped, cylindrical; pointed, 

 hooked, or knob-shaped at the tip. They may be regarded as merely 

 prominent hymenial hairs with the probable function of protecting the 

 basids, or of parting the appressed lamellae. They have been the 

 subject of much idle speculation, and among other erroneous views they 

 have been regarded as male organs. 



In ^the sporophores of many Agarici'ni, notably of Lactarius (Fr.), 

 laticiferous hypha occur, which yield considerable quantities of milky, 

 generally acrid, juice when the tissue is bruised. 



