186 DIVISION II.—COURSE OF DEVELOPMENT OF FUNGI. 
The sporocarps are formed and borne in some species on an inconspicuous 
filiform mycelium, and then exhibit the characters of compound sporophores described 
in sections XII and XIII. In other species they are produced and borne 
on larger compound sporophores, each called a séroma, which take the form 
in the different species of flat expansions, crusts, foliaceous or erect and branched 
shrublike bodies. The general structure and conditions of growth of these forma- 
tions, which are often of considerable size, have also been described above in 
section XII. Well-known examples of them among the Pyrenomycetes are the 
cushion-like or membranous expanded stromata of the ‘Sphaeriae compositae,’ i. e. 
of the genera Hypoxylon, Diatrype, Ustulina, Epichlo&, and many others, and the 
erect sporophores of the Xylarieae, Claviceps, Cordyceps, Thamnomyces with its 
many bifurcations, and others. Of the Discomycetes which belong to this group 
the most important are the Lichen-fungi with their disk-shaped and alveolate sporo- 
carps; next, Rhytisma and its allies with 
flat disk-shaped stromata, and perhaps too 
the remarkable South American Cyttarieae 
—spherical or club-shaped or gelatinous 
bodies more than an inch in diameter 
with the broad upper half covered with 
deeply alveolate hymenia, regarding which 
it is doubtful whether each is in itself a 
sporocarp or a portion of the sporocarp 
formed by the whole club-shaped stalk. 
Two chief constituents may be dis- 
tinguished in almost all the better-known 
sporocarps of the Ascomycetes (Fig. 85) ; 
one (c, s, a) is the ascus-apparatus and 
consists of asci together with the hyphae 
_ or cells from which they are immediately 
Fic. 85. Ascobolus Jurfuraceus. Young sporocarp in es 
median longitudinal section ; une derived, the ascogenaus hyphae or ascogenous 
layer and the asl a shaded antheräal branch, 4-7 dasıe cells ; the other is the envelope-apparatus 
matic representation from Sachs after Janczewski. which is formed of all the other parts of the 
sporocarp. The two parts are necessarily 
in the closest relation to one another from the purely morphological and also from 
the physiological point of view, since the envelope-apparatus bears, protects, and 
feeds the asci. The elements of the two parts may be most intimately united 
and interwoven with one another in the mature sporocarp and in fact may be 
difficult to separate or distinguish. Nevertheless the origin and growth of the 
two parts are usually distinct from their first inception or at least in a very early 
stage of the sporocarp, so that only similar parts, asci, and not elements of the 
envelope, spring from an ascogenous hypha or ascogenous cell, and no asci from 
the elements of the envelope. Exceptions to this rule are according to ac- 
curate observations at least very rare. Former statements to the effect that. asci 
and elements of the envelope, especially paraphyses, spring directly from the same 
‘hyphae are in most cases certainly incorrect; even some recent statements, like 
those regarding Pleospora and Ascodesmis, which will be noticed again in a 


