108 MR. GEORGE MASSEE ON THE THELEPHORES. 
becoming exposed only when the spores are ripe for dispersion. 
The two extremes are connected by transitional forms. In this 
particular we have shadowed in the Hymenomycetes a feature 
highly characteristic of the Gastromycetes, in which the hymenium 
is completely surrounded by a specialized portion of the sporo- 
phore until the spores are mature. Here, again, the two sub- 
groups are connected by intermediate stages. 
It is not to be inferred that the concealment of the hymenium 
until maturity implies a higher phase of development in the Gas- 
tromycetes. In both subgroups a common idea is aimed at: this 
is to expose the greatest possible amount of hymenium or spore- 
bearing surface in the smallest possible space. In the higher Hy- 
menomycetes this is effected by means of closely-packed radiating 
plates or lamelle ; whereas in the Gastromycetes the same object 
is attained by the development of a complicated labyrinthiform 
or cavernous mass, the cavities of which are lined with the hy- 
menium, and the naked or concealed hymenium is the outcome 
of this twofold arrangement respectively. In the Hymenomycetes 
the basidia are typically club-shaped terminal branches of hyphe, 
each furnished with four slender outgrowths, called sterigmata, at 
or near the apex; each sterigma produces a spore at its apex 
(Pl. XLVI.fig. 12). In some of the simpler forms the basidia 
have only two sterigmata, and, in rare instances, only one*. The 
spores are simple (unicellular) except in the Tremellinee, where 
they are in many species compound, consisting of four cells (tri- 
septate), sausage-shaped and slightly eurved. 
The fact of a plant producing compound spores is not to be 
considered as a sign of higher organization than in the case of 
another producing simple spores; neither is the reverse of this 
true. Nevertheless, in many instances where the original simple 
spore becomes broken up by septa into several cells, it suggests 
to the mind a closer relationship with vegetative structures than 
* In Sachs's ‘ Text-Book of Botany,’ Engl. ed. p. 338, in describing Agaricus 
campestris, the following sentence occurs :—‘ Each basidium produces in this 
species only two, in other Hymenomycetes usually four spores." Thisis not cor- 
rect ; the basidia of 4g. campestris have four sterigmata, each producing a spore ; 
nevertheless this strange error has been repeated and accompanied by the equally 
incorrect woodcut in several English works on Botany. Correct figures of the 
basidia are given by de Seynes, * Essai d'une Flore Mycologique de la Mont- 
pellier; pl. 4. f. 12; Balfour's ‘ Class-Book of Botany,’ 3rd ed. p.21, fig. 40, &c. 
The plant itself is not uncommon. 
