246 DIVISION II.—COURSE OF DEVELOPMENT OF FUNGI. 
(6) Dense hymenia giving off gonidia by abscision on the free ouler surface of 
compound sporophores. Examples of this kind are Claviceps (page 227), Epichloe, 
the Nectrieae before mentioned, Xylarieae (Fig. 103 A), Cucurbitaria macrospora 
(Fig. 117), and many others. The form of the separate gonidiophores which together 
constitute the hymenium, the special mode of abjunction of the gonidia, and the 
structure and form of the gonidia themselves, all vary extremely according to the 
species. And again it depends on the species whether the formation of gonidia is 
entirely, or almost entirely, confined to these hymenia or to the stromata which bear 
them, as is the case in Nectria cinnabarina and the other genera last named, or 
whether gonidia-forming hyphae of like structure occur either united into hymenia 
or appearing singly on a filamentous mycelium as in the Hyphomycetes, as happens 
in Nectria Solani and Hypomyces Solani’. 
Whether we have always to do with gonidia in the cases which have been given 
as examples, especially in the Xylarieae, or sometimes also with non-germinating 
spermatia, is often uncertain and must be determined in each separate case. 
(c) Pycnidia: receptacles (conceptacles) of more or less similar character to 
those described in Pleospora, and producing gonidia which are known as pycnospores 
or pycnogonidia or more commonly as 
stylospores. They are wanting in many 
or most species of Ascomycetes, in all 
forms, for instance, mentioned under 6 
and in most of those mentioned under a, 
and in almost all Lichen-fungi. They 
were said indeed to have been found by 
Lindsay in Bryopogon jubatus, Kbr., 
Imbricaria saxatilis and I. sinuosa, Kbr.; 
by Gibelli in ‘ Verrucaria carpinea, Pers.,’ 
Sagedia carpinea, Mass., S. Zizyphi, 
Mass., S. callopisma, Mass., S. Thuretii, 
FIG. 117. Cucurbitaria macrospora, Ces.andde Not. a stroma. 5 m y 
in longitudinal section ; ? developed perithecium, c layer of gonidia. Kbr., Pyrenula minuta, Näg., P. olivacea, 
amo ee Der Verqoaria Gibelliana, Garov.; by 
Fiiisting in Opegrapha varia, Acrocordia 
gemmata, Mass., A. tersa, Sagedia netrospora, Hepp., and S. aenea. "Lindsay's account 
also of two kinds of spermogonia in Roccella Montagnei, Bel. and Opegrapha 
vulgata, Ach. may be mentioned here since some of the receptacles which he termed 
spermogonia may be pycnidia. But in all these cases we know so little concerning 
the development of the organs in question that it is still uncertain whether they belong 
to the species named above or to parasites living in their thallus. 
The pycnidia, like the perithecia, are according to the species either formed 
singly from the filamentous mycelium, or are placed in or on compound pycnidio- 
phores (stromata), as in Cucurbitaria Laburni, Dothidea Melanops, &c.? Their 
development proceeds, in several cases that have been observed, in the manner 


' Reinke u. Berthold, Die Zersetzung d. Kartoffeln durch Pilze, 1879. 
* Tulasne, Carpol. II. 
