CHAPTER V.—COMPARATIVE REVIEW.---HFYMENOMYCETES. 287 
club-shaped bodies described above producing two or four, seldom a larger number 
of spores. No great deviations from the ordinary rule occur except in the Tre- 
mellineae and a few exceptional genera, as Tulostoma (section XC) and Kneiffia’, 
in which latter the basidia are said to produce only one spore. The ripe spore is 
always abjointed as a single cell, except in a few Tremellineae and the doubtful case 
of Agaricus rutilus?, and exhibits every gradation in form from spherical to narrowly 
fusiform. 
Hymenomycetes and Gastromycetes are distinguished from one another by 
the structure of their compound sporophores, which we will now proceed to describe. 
HyYMENOMYCETES. 
Section LXXXV. This division differs from the other in having the hymenium 
on the free outer surface of the compound sporophore at or more commonly before 
the time of the abjunction of spores. In the simplest cases, such for example as 
are presented by Corticium, Dacryomyces, Exobasidium, and some species of 
Hypochnus, the compound sporophores do not vary essentially in form and 
differentiation from the layers of teleutospores in the Uredineae, such for instance as 
the layer shown in Fig. 130, if basidia are substituted for the teleutospores. They 
are therefore flat or cushion-shaped bodies which bear the hymenial layer on the free 
surface and are attached by the opposite surface to the mycelium or substratum. From 
these which are the simplest forms there is a passage into more-highly developed forms 
and chiefly in two directions. In the one case the substratum is vertical and the 
margin of the compound sporophore which points upwards raises itself from the 
substratum and continues to grow nearly at right angles to it; in this way fan-shaped, 
mussel-shaped, or horse-shoe-shaped sporophores are formed, bearing the hymenium 
on the surface which looks towards the ground and sterile on the opposite side. In 
the other case the compound sporophore rises in a vertical, erect position from 
the usually, if not always, horizontal substratum and takes the form of the Cap-fungi 
and club-shaped Hymenomycetes. The former are obconical bodies or funnel- 
shaped or umbrella-like and borne on a stalk; in a few cases the hymenium is on 
the surface which is turned away from the substratum, and therefore on the upper, 
inner surface in the funnel-shaped form, while the rest of the surface remains sterile, 
as in Cyphella, Guepinia, Tul. and Exidia. Generally the opposite is the case, and 
the hymenium is localised on the side towards the substratum, on the surface of 
the cone and the lower surface of the stalked umbrella, as in Gyrocephalus of Persoon 
( = Guepinia helvelloides, Fr.) and most of the Hymenomycetes in the narrow use of 
the word. In compound sporophores of the latter kind the portion to which the hy- 
menial surface belongs has the special name of cap or pileus, and is placed on a more 
or less distinct s/a/k, the sfifes. The term cap or pileus has been extended for 
convenience sake from this its original signification to the compound sporophore 
generally in which the hymenial surface looks towards the ground, and therefore 

1 Fries, Hymenomyc. Europ. p. 628. Berkeley and Broome in Ann. and Mag. of Nat. Hist. 
ser. 4, VII, p. 429. 
2 Léveillé in Ann. d. sc. nat. ser. 2, VIII, 328. 
