THE MUSHROOM 111 



sents a slightly magnified portion of a tangential section 

 of the pileus (h), showing the gills (I), which are evidently 

 extensions of the hyphae of the pileus modified into 

 delicate plates. B is a section of a single gill, magnified 

 about 80 diameters, to enable us to note the structure. 

 We observe the trama (t) formed from hyphse emergent 

 from the pileus ; sh is a layer of short, closely packed cells, 

 called the " sub-hy menial layer " ; while hy is the hy- 

 menium, composed of cells which are at right angles 

 to the surfaces of the gill. The hymenium (Gr. humen, a 

 membrane) is the spore-bearing part of the gill. It is 

 formed of well-nourished club-shaped cells, some of 

 which do not produce spores, and are more slender than 

 the others; they are the paraphyses (Gr. para, beside; 

 phusis, growth). The remaining cells of the hymenium 

 are stouter than the sterile cells; they are the basidia, 

 from which the Order Basidiomycetes gets its name, and 

 they are specialized for spore production. In C of our 

 figure we have a part of a gill section magnified 370 

 diameters; if is a portion of the trama ; sh, the sub- 

 hymenial layer, and the cells standing out at right 

 angles are cells of the hymenium. The letter q stands 

 for the paraphyses ; s 1 -s i show the basidia in various 

 stages of growth. The basidia produce little apical 

 outgrowths, from two to four to each basidium, and each 

 outgrowth produces a spore (sp). Millions of spores 

 are developed in a single fruit. 



The spores produced from a basidium are termed 

 " basidiospores." They are the only kind of spores 

 occurring in the Basidiomycetes, in which Order sexual 

 organs are entirely wanting. The Suborder Hymeno- 

 mycetes has the hymenium naked, and in the mature 



