24<5 



DIVISION II. — COURSE OF DEVELOPMENT OF FUNGI. 



(b) Dense hymenia giving off gonidia by abscision on the free outer surface of 

 compound sporophores. Examples of this kind are Claviceps (page 227), Epichloe, 

 the Ncctrieae before mentioned, Xylarieae (Fig. 103 A), Cucurbitaria matrospora 

 (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 Ilyphomycetes, 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 pyenospores 



or pyenogonidia or more commonly as 

 stylospores. They are wanting in many 

 or most species of Ascomycetcs, in all 

 forms, for instance, mentioned under b 

 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, 

 Kbr., Pyrenula minuta, Nag., P. olivacea, 

 Pers., Verrucaria Gibelliana, Garov. ; by 

 Fiii sting 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 pyenidio- 

 phores (stromata), as in Cucurbitaria Laburni, Dothidea Melanops, &c. 2 Their 

 development proceeds, in several cases that have been observed, in the manner 



FIG. 117. C ncurbitar ia macrospora, Ces. and de Not. 1/ Stroma. 

 in longitudinal section ; /developed perithecium, r layer of g< 

 b gonidia on the gonidiophores. After Tulasne. a slightly magnified, 

 b magn nines. 



1 Reinke u. Berthold, Die Zcrsetzung d. Kartoffcln durch Pilze, 1879. 

 z Tulasne, Carpol. II. 



