2IO DIVISION II. — COURSE OF DEVELOPMENT OF FUNGI. 



hyphae begin to shoot out from the sterile sister-branches of the archicarp and from 

 the whole of the rest of the basal region of the rosette to form the envelope-portion 

 of the sporocarp (Fig. 98), consisting of a receptaculum enclosing the group of 

 archicarps and antheridia and the hypolhecium with the paraphyses, which latter 

 always rests free on the receptaculum without an enveloping wall. The dis- 

 tribution of the ascogenous hyphae and asci and the gradual multiplication of the 

 latter between these elements of the envelope are essentially the same as in Ascobolus. 

 The paraphyses form at first a conical tuft on the hypothecium, which generally 

 broadens out into a disk through the introduction of new elements. The receptaculum 

 becomes a comparatively large thick large-celled pseudo-parenchymatous disk covered 

 with rhizoids, and between its elements those of the primary rosette are inclosed, and 

 are at length indistinguishable (Fig. 99). The antheridia continue longest visible and 

 indeed almost unaltered, being very full of protoplasm, and take no part in the formation 

 of the envelope. 



7. In Sordaria among the Pyrenomycetes especially S. (Hypocopra) fimicola and 

 in Melanospora parasitica the course of development in the perithecium, according 

 to Gilkinet's and Kihlman's researches, is essentially the' same as in Ascobolus, of 

 course with certain specific differences, and with differences of conformation corre- 

 sponding to the difference between Discomycetes and Pyrenomycetes. The archicarp 

 is a spirally coiled cell-row, though in Melanospora it is sometimes almost straight. 

 Antheridial branches are less plainly seen in Melanospora, or at least are not sharply 

 distinguished from the incipient filaments of the envelope, which here too grow 

 close round the archicarp soon after its formation. In Sordaria the growing 

 archicarp divides by transverse walls into numerous cells, and ascogenous hyphae 

 sprout from the great majority of these cells ; whether any portion of the archicarp 

 takes no part in their production could not be determined owing to the early gelatinous 

 disorganisation of the walls of all its cells. In Melanospora only one or two cells in 

 the middle of the large archicarp become ascogenous, the rest being disorganised 

 and afterwards partly ejected in this state from the orifice of the young perithecium. 

 These one or two ascogenous cells develope by successive bipartitions in varying 

 directions into a parenchymatous body, the many cells of which are full of protoplasm 

 and subsequently produce the asci. These are arranged in Sordaria nearly parallel 

 to one another in a thick tuft, in Melanospora they form a nearly spherical body, and 

 their apices converge towards its middle. In both cases the many-layered pseudo- 

 parenchymatous wall of the perithecium is formed from the weft of hyphae of the 

 envelope. It is a spherical body at first closely surrounding the future group of asci 

 on every side, the neck and the canal of the ostiole being formed in it later. There 

 are no paraphyses standing between the asci; these are placed separate and beside 

 each other on a surface of insertion which covers a part of the interior of the sphere. 

 On the side left free from the paraphyses there is a narrow empty space between tin- 

 wall and the ascus-group, but this is soon filled with a large number of closely packed 

 livphal branches, which grow into it as periphyses from the wall, converging radially 

 till they touch one another. The group of these which is mostly turned away from 

 the asci then grows vertically towards the wall in the direction of the neck which is 

 to be, and so on to the outside through a hole in the wall, and thus forms the 

 commencement of the neck, which may lengthen out considerably, and in Sordaria is 



