11. INTRODUCTION. 



and in many cases constitutes the entire plant. That portion of the receptacle in which the 

 reproductive bodies are imbedded is called the hymenium ; it is either external (Hymenomy- 

 cetes), as in the Agaric, where it forms gills ; or included (G aster omycetes), as in the Puff-balls. 



The receptacle is either placed upon a stem (stipitate) or stemless (sessile) ; and sometimes 

 spread in thin membranous patches (effused). 



Having made these preliminary general observations, which apply to the whole Fungus 

 family, we proceed to the first great division. 



Order I. HYMENOMYCETES.' 

 Tribe I. PILEATI. 



Eeceptacle dilated more or less in a horizontal dii'ectiou, sometimes branched, tending to an orbicular form. 

 Hymenium inferior. 



Named iroxu_pileus a cap " the common head-covering of freedmen among the Romans, 



and therefore given as a reward to such gladiators as were slaves, in token of their being 



made free ". The pileus of Funguses is however the entire head of the plant, not a mere 



head-covering. It is generally placed upon a stem, and indeed is a prolongation of it ; " on 



dividing an Agaric or Boletus perpendicularly, it will be perceived that the stem extends itself 



into a body in the form of a parasoP". Beneath its shelter lies the fructifying membrane, 



scientifically defined Hymenium inferior. " In the hymenomycetous tribes, the essential 



character appears to consist in a hymenium composed of closely packed sporophores, which 



support on spicules a generally determinate number of spores*". In the Cupulate and Elvel- 



laceous kinds the reproductive bodies are placed in cases, occasionally septate, which cases 



are called asci or thecse. In stemless plants, the pileus is frequently, not merely sessile, but 



also re-swpinate, that is, lying on its back, with the hymenium upwards ; but this position 



there is an evident tendency to correct, one edge of the pUeus often rising, turning over, and 



liecoming what is called in that case rejlexed. 



To this tribe, Pileati, belong the Genera : — 



1 . A.GAEICUS. — Hymenium consisting of plates {lamella) radiating from a common centre, with shorter ones iu 



the interstices ; composed of a double closely-connected membrane, more or less distinct 

 from the pileus. 



2. CANTHAUELLUS. — Hymenium dichotomous, radiating, branched folds, not distinct from the pileus. 



3. MERULIUS. — Hymenium veiny, or forming unequal angular or fiexuous pores, not distinct from the pileus. 



' From vfitfv, a membrane, and /nJ/ct^t, a fungus. ^ Persoon. ^ Berkeley, 



J 



