2HH DIVISION II. — 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 Thcle- 

 phoreae. 



The hymenial 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, lamellae, 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 {Jubuli, 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 



