CHAPTER V.—COMPARATIVE REVIEW.—GASTROMPFCETES. 309 
which anastomose with one another in every direction and pass on one side into the 
tissue of the peripheral peridium, on the other it may be into that of the central 
column, seeming as if they radiated from it. The chambers of Polysaccum are larger, 
of the size even of a pea, and are less irregular. 
The chambers are in most cases in countless numbers; they form altogether 
a mass of tissue which is distinguished from the adjoining tissue by its chambered 
structure and by the formation of spores and is known as the gleba. 
As regards the more minute structure, we may distinguish a middle layer or 
trama in the walls of each chamber, and a Aymenzal layer, on both surfaces of the 
trama. The two parts (Fig. 142) resemble in all essential points the parts of the 
same name in the Hymenomycetes. In the cases which have been most thoroughly 
examined (the Hymenogastreae, Phalloideae, Lycoperdon, Bovista, Scleroderma, Geas- 
ter) the trama is formed of a weft of copiously branched hyphae, which chiefly run 
parallel to the surface of the walls, and pass without interruption from one chamber- 
wall to the adjoining ones and into the tissue 
of the peridium. Numerous closely packed 4 
branches from the hyphae of the trama run 
towards the interior of the chambers, and there 
form the hymenial tissue. In some cases they 
are comparatively short, of uniform height and 
placed palisade-like side by side and perpen- 
dicularly upon the surface of the trama; thus 
they form a sharply defined hymenial layer 
which lines the empty cavity of the chamber 
and is exactly like that of the Hymenomy- 
cetes (very many Hymenogastreae (Fig. 142), 
species of Geaster, Lycoperdon, Phallus). In 
another series of cases (Melanogaster, Sclero- 
derma, Polysaccum, Geaster hygrometricus), 
all the hyphae which entera chamber from the _rıc. 112. Octaviantaasterosperma Vitt. Thin section 
hymenium are elongated, copiously branched, Seh are, eg bras Geese Punt 
and -woven together into a weft which fills a nn iileraika 
the chamber. j 
-The special formations also of basidia and paraphyses in most Hymenogastreae 
scarcely differ at all from those of any Hymenomycetes except the Tremellineae. The 
basidia of some Lycoperdaceae and Phalloideae, described already on page 63, vary 
a little more from them, but only in points of special conformation. Those of Geaster 
tunicatus and Tulostoma are strangely shaped objects; the former are ellipsoid to 
flask-shaped vesicles with a narrowly conical neck, the apex of which puts out about 
six sterigmata which abjoint spores; the latter (Fig. 143) are narrowly club-shaped 
cells which abjoint four almost unstalked round spores on their lateral faces. 
t. There is not much to add to what has been already said of the Hymeno- 
gastreae. The gleba retains the structure which has been described from the 
cominencement of its formation to its perfect maturity (Fig. 141). Its tissue is 
all- the while either fleshy and formed of thin-walled juicy cells, the interstices 
conveying ait or fluid, as in Hymenogaster Klotzschii, Tul. and Octaviania carnea, 

