CHAPTER V. — COMPARATIVE REVIEW. — ASCOMYCETES. 



189 



The Ascomycetes which bear apothecia are well known under the name of 

 Discomycetes and Gymnocarpous Lichens. The apothecia in the largest species 

 are compound sporophores of considerable size with limited growth in the direction of 

 the apex or margin, club-shaped or cochleariform in Geoglossum, Spathulea, &c, a 

 stalked cap in Morchella, Helvella, Leotia, Verpa, and others. The early stages 

 of the development of these bodies are little known, but they may be ranked as 

 sporocarps with the forms which will be mentioned directly on account of similarity of 

 structure, and the presence of intermediate forms, especially the large stalked Pezizae. 

 The most characteristic and frequent form is that of the roundish or oblong disk-shaped 



FIG. 88. Anaptychia ciliaris. Small piece of a vertical section through an apothecium ; m medullary layer of 

 the thallus, y subhymenial layer, p paraphyses with asci between them. The numerals 1—4 represent successive 

 stages in the development of the spores. After Sachs. Magn. 550 times. 



hymenia, which are plane, convex or concave, and in the latter case usually like a bowl 

 or cup, on a stalked or sessile receptaculum or excipulum, as in the Pezizae and in most 

 gymnocarpous Lichen-fungi. The usual mode of growth by gradual advance towards 

 the apex or margin does not prevent the appearance of intercalary surface-growth, which 

 does in fact occur very often and with very varying distribution of the preferred places 

 of growth ; and this may produce a variety of changes in the original shape of the 

 hymenial surface, such as splittings and prolifications, the latter producing a very peculiar 

 and characteristic form in Gyrophora '. For the details of these phenomena, which 

 have yet to be more certainly ascertained in many points, we must refer the reader to 



1 See Krabbe in Bot. Ztg. 1882, Nr. 5-8. 



