462 SYSTEMATIC BOTAXY. 



which is the receptacle of the hymenium. Hymenium bearing 

 usually quaternately asexual spores at the apex of erect basidia. 

 Spores reproducing the plant directly without the intervention of 

 any intermediate generation. Mycelium comparatively small and 

 floccose. The Order may be divided into the following Sub- 

 orders : 



Suborder 1. TREMELLHSTI. Fungi growing on stumps of trees 

 and on the ground, of a gelatinous consistency, with sometimes a 

 denser nucleus, immarginate or cup-shaped. Hymenium bearing 

 two distinct kinds of basidia in different genera. Spores reniform, 

 in some cases divided, and in others not. Illustrative Genera: 

 Tremella, Dill. ; Dacrymyces, Nees. 



Structure and Life-history. In the genus Tremella the basidia are 

 at first subglobose or quite spherical, and divided from top to bottom 

 into four equal parts. These segments either remain united or become 

 divergent from each other, while they grow out to the margin of the 

 fungus in the form of long- hyphse, and produce there generally undivided 

 and kidney-shaped spores. In Dacrymyces and Guepinia the basidia 

 are at first claviform, but subsequently grow out in the form of two thick 

 diverging arms, on each of which is produced one reniform spore. 



There are usually present in these plants in great abundance very mi- 

 nute spherical or ovoid spermatia, produced in regular sperm at ophorous 

 apparatus. Their function is unknown. The ordinary spores reproduce 

 the plant directly. The consistence of these plants is very gelatinous and 

 collapses on drying. If, however, they be placed in water, they very soon 

 absorb it, and become again distended to their former extent ; and this pro- 

 perty is found to be of great use in examining old specimens. 



Suborder 2. HYMEISTOMYCETES. Mycelium floccose, giving rise to 

 a superficial hymenium on which are produced clavate basidia 

 bearing at the apex usually quaternately, slightly stalked or 

 sessile spores. The substance of the plants varies from gelatinous 

 to woody. Illustrative Genera : Agaricus, L. ; Boletus, Fr. ; Poly- 

 porus, Fr. ; Hydnum, L. ; Corticium, Er. ; Clavaria, L. 



Structure and Life-history. This group is the best known of all the 

 Fungi, and includes the common Mushroom, to which all its members bear 

 more or less resemblance in organization and reproduction. The common 

 form is that of a pileus raised upon a stalk or stem, and bearing on the 

 under surface lamellae or gills (Agaricini),ipQTes (Polyporei), or teeth (Hyd- 

 nacei), on the surfaces of which are situated the basidia, which bear the 

 spores (fig. 515). The spores are the only reproductive organs and, so far 

 as is yet known, are asexual in their .origin. On germinating, they give 

 rise directly to a new mycelium, which bears again the spore-producing 

 plant. Attempts have been made at different times to discover the exist- 

 ence of a sexual agency in the production of these spores, but as yet un- 

 successfully. Among the basidia are seen other cells of similar shape and 

 usually larger size, called cystidia; and it was at one time contended that 

 they were male organs but no special function seems to belong to them. 

 They are probably only barren basidia. The mycelium is entirely, or 



