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INTRODUCTION TO THE STUDY OF FUNGI 



surmounts the stem or carpophore, and bears on its under sur- 

 face the hymenium or fructiferous surface. It follows the 

 same type in the Agaricini, Boleti, some Polyporei, and Hydnei. 

 This type is a convex, or primarily convex, orbicular expansion 

 of the apex of the stem, with a more or less distinct pellicle on 

 its upper surface, an intermediate stratum, and its lower sur- 

 face covered by the hymenium. In this type, then, it is a 

 hymenophore, as it is in other forms of Hymenomycetes. This cap 

 (Fig. 16) not only surmounts, but it is continuous with the stem, 

 and for the most part conforms to it in texture. In some 

 cases it passes down in plates on the under surface between 



Fia. 16. — Agaric. A, young ; B, mature ; C, section ; p, pileus ; 

 s, stipe ; v, volva ; g, lamellae or gills ; a, annulus or ring. 



the folds of the membrane which bears the hymenium, and is 

 the trama. The superior cuticle or pellicle is sometimes so 

 distinct from the subjacent stratum that it may be stripped 

 off, but in other species it is so intimately incorporated with 

 the substratum that it is inseparable. From the margin of 

 the cap this cuticle is sometimes extended inwards and united 

 to the stem, covering the young hymenium, and forming a veil. 

 Externally the cuticle may be quite dry or viscid, or even 

 covered with a slimy gluten, as in Agaricus mucidus and 

 Agaricus aeruginosas. In some cases the cuticle is compara- 



