288 DIVISION 11.—COURSE OF DEVELOPMENT OF FUNGI. 
also to those which have the shape of a horse-shoe or fan. The club-shaped Hy- 
menomycetes are erect, club-like or cylindrical, unbranched or branched shrub-like 
bodies, and have their upper part covered all round with the hymenial surface. 
Calocera, Dacrymitra, and the Clavarieae are well-known examples of this subdivision. 
A very extensive and almost unbroken series of intermediate forms connects 
the chief forms specified above, and is most complete in the group of the Thele- 
phoreae. 
The Aymenzal surface shows considerable variety of formation, to some extent in- 
dependently of the general form of the compound sporophore, and this variety has been 
the chief means employed to distinguish the groups and genera of the Hymenomycetes 
in the narrower sense. It is smooth or in large irregular folds, and sometimes has 
also slight prominences, hair-structures, and similar formations, as in most of the 
Tremellineae, Clavarieae, and Thelephoreae. In other groups it is considerably 
enlarged by peculiar projections of definite shape ; by teeth or regularly conical sharp- 
pointed spikes in Tremellodon and the Hydneae ; by plates, /amel/ae, something like a 
knife-blade in shape, which radiate towards the margin of the pileus in the Agaricineae, or 
are concentric with the margin in the genus Cyclomyces; lastly, in the Polyporeae 
by folds or plates connected together into a reticulation, which are either shallow 
(Merulius, Favolus), or grow to such a height that the meshes become comparatively 
long narrow tubes (éudul?, pori) united laterally to one another and bearing the 
hymenium on their inner surface (Polyporus, Boletus). Between these forms also, 
which in their extreme condition are very characteristic, there is no lack of inter- 
mediate states. A larger or smaller number of transverse connections between 
lamellae or teeth may make a species or even individuals of the same species 
occupy a doubtful position on the border-line between Agaricineae and Polyporeae, 
or between Hydneae and Polyporeae, and so on. The genera Irpex, Lenzites, 
Daedalea, Cantharellus, &c. supply numerous instances of the kind, and should be 
studied in descriptive works. 
In by far the great majority of cases the construction of these compound sporophores 
is by progressive growth of a primordial bundle of hyphae in the direction of the margin 
or apex. There may at the same time be intercalated areas where growth continues 
longer or recommences, but this point is not certainly ascertained. The instances of 
progressive growth of the compound sporophores given in the general description 
at page 50 are chiefly taken from the Hymenomycetes, and the reader is referred to 
them for further information. Where the hymenial surfaces have projections, it is a 
general rule that they retain on the average the same shape, and especially the same 
breadth and distance from one another over the whole extent of the surface. The 
absolute number of the projections must therefore increase in proportion to the growth 
of a fan-shaped or cap-like sporophore at the periphery. This is effected in lamellae 
which radiate towards the margin either by bifurcation of the original lamellae, as in 
Cantharellus, Daedalea, and some species of Lenzites, or all lamellae when once 
formed grow radially marginwards without branching, and new ones are formed 
between them from the point where the distance between the old lamellae exceeds a 
certain measure; this is what happens in most Agaricineae. Hymenial surfaces 
therefore of this kind come to have successively formed lamellae, which, starting from 
the margin, either extend as they were first formed to the point of insertion of 
