288 H. MARSHALL WARD. 



and soon disappears. Its immediate neighbour (i. e. the eel. 

 below the apex) becomes cut up by numerous septa in all 

 planes, and forms an ascogenous core of parenchymatous tissue. 

 As this occurs, the internal layers of the now dense envelope — 

 produced by repeated ramifications and divisions of the inter- 

 weaving hyphse of the enveloping branches — become dis- 

 organised, deliquescent, and evidently then serve as nourishment 

 for the cells of the ascogenous core.^ The proximal cells (i.e. 

 those cells between the ascogenous cells and the mycelium) of 

 the ascogonium also disappear, and the enveloping layers around 

 them become elongated to form the long neck of the perithe- 

 cium. It thus comes about that the free apex of the ripe 

 perithecium corresponds to what was the attached end of the 

 ascogonium. 



The walls meanwhile become coloured deep brown, and 

 rudimentary paraphyses spring from their internal layers. The 

 asci arise from the colourless cells of the ascogenous core, in 

 which a cavity is produced by the tangential growth of its 

 peripheral cells. 



In the concluding remarks stress is again laid upon the fact 

 that we cannot speak of an antheridium here ; the antheridia 

 have degenerated to mere vegetative hyphse, and the ascogenous 

 core produces its asci without any sexual process whatever. A 

 single cell produces the asci. In most respects this agrees with 

 Gilkinet's description of the analogous processes in Sordaria 

 fimicola.^ But in Sordaria, Gilkinet finds one enveloping 

 hypha apply itself to the ascogonium before the rest, though he 

 could not decide that copulation took place. ^ Kihlmanu denies 

 that this can be termed an " antheridium." He regards 

 Melanospora as somewhat midway between those Erysi- 

 phese which, like Eurotium and Podosphaera, have the 

 sexual organs at least morphologically present, and the truly 



' Cf. my description of the development of the peritliecium in Meliola, 

 Phil. Trans./ 1883, p. 592, &c. 

 - ' Bull, Acad. r. de Belgi'que,' ser. 2, t. xxxvii. 



3 Cf. also De Bary and Worouiu, ' Beitr. zur Morph. uud Phys. der Pilze, 

 &c.,' 1870, R. iii. 



