238 THALLOPHYTES. 



the zoospores, must be regarded as the second generation, while the zoospores 

 may be compared homologically with the spores of Mosses. 



In Nemalion (C) the carpogonium w consists also of a single cell which is wide 

 below and narrow and elongated above. This elongation, termed the Trichogyne^ 

 is a closed tube; the male fertilising cells attach themselves to it, empty their 

 contents into it, and thus incite a further development of the basal part of the 

 female cell, which now increases in size, and divides into a number of cells which 

 grow out into densely crowded branches. A spore is formed at the end of each 

 of these branches; and the whole assemblage of spores together with its short 

 pedicel constitute the sporocarp, which in this case has no envelope. 



In the true Floridese, of which Nemalion may be considered the simplest form, 

 the carpogonium w consists, even before impregnation, of a number of cells {D) ; 

 a lateral row of cells bears at its apex a closed hair-like prolongation, the tri- 

 chogyne, and is hence termed the Trichophore. The trichogyne receives the fer- 

 tilising substance from the male cells which become attached to it ; but neither the 

 trichogyne itself nor the trichophore is thereby excited to any further development, 

 the sporocarp resulting from the other cells of the carpogonium which lie beside the 

 trichophore. The fertilisation therefore takes effect at a distance from the spot to 

 which the male cell has attached itself. Certain cells of the carpogonium grow, 

 divide, and finally produce the stalked spores, the pericarp or envelope of the fruit 

 arising, as the result of branching beneath the carpogonium. 



The sporocarp of the Characese {B\ which has hitherto been without any 

 analogy, becomes intelligible if we compare it on the one hand with that of the 

 Coleochaetese, on the other with that of the Florideae. The carpogonium w 

 consists of a large ovoid cell which is borne on certain small round basal cells 

 (Braun's ' Wendezellen '). These basal cells take no part in the development 

 brought about by fertilisation, their behaviour being similar to that of the 

 trichophore of the Florideae. The large cell is fertilised by filiform antherozoids, 

 and itself forms the single carpospore in the sporocarp, the envelope of which 

 has been completely developed before fertilisation ; and it behaves also in other 

 respects in a similar manner to that of the Coleochgeteae, Florideae, and Erysipheae. 

 That the large cell which becomes the carpospore does not possess any hair-like 

 receptive organ or trichogyne is a point of very subordinate importance, since in 

 the carpogonium of the Ascomycetes this organ is sometimes present, sometimes 

 absent \ 



One of the simplest cases of the formation of the fructification in the 

 Ascomycetes is afforded by Podosphcera {^); and we here get the transition to 

 an evident alternation of generations. The carpogonium 7v consists of a single 

 cell, and is fertilised by another tubular cell, the pollinodium. The result of fer- 

 tilisation is that the female cell grows, and divides into two cells, of which the 

 upper one forms in its interior several spores (Ascospores), and is hence termed 

 the Ascm. Beneath the pedicel- cell of the ascus shoot out filaments which form 

 the envelope of the fructification y. 



The processes are somewhat more complicated in Ascoholiis, another Asco- 



See De Bary, Btitrage zur Morphologic u. Physiologic cler Pilze, vol. III. p. 



