CHAPTER V. COMPARATIVE REVIEW. ASCOMYCETES. 199 



formed separately from the archicarps in special layers or receptacles, the 

 spermogom'a, and give off small spore-like cells, the spermatia, by abscision. The 

 spermatia are conveyed to the archicarp and to a special receptive process of it, 

 the trichogyne, and conjugate with it. These phenomena correspond in part, and, 

 excepting in some points of detail which will be described further on, to those 

 observed elsewhere in distinct sexual organs and processes, and without them the 

 sporocarp is not developed. The organs here described in the Ascomycetes are 

 therefore to be regarded in the above cases as sexual organs, the archicarps as the 

 female, the antheridial branches or spermatia as the male organs. 



In the Erysipheae, Penicillium, Sordaria, and Gymnoascus conjugation has not 

 been observed, but the union of the two kinds of organs is as firm as it is invariable. 

 Their sexual function therefore has not been certainly proved, but it may be 

 assumed to be highly probable. 



The antheridial branches are less constant and less distinct in Ascobolus and 

 Melanospora. According to present observations they are not to be clearly dis- 

 tinguished from the first envelope- filaments that grow round the archicarp; their 

 sexual function must therefore be considered to be undetermined. The question of 

 the homologies is not hereby prejudged, as will be explained in section LXVI. 



3. An archicarp is formed in the compact thallus of Polystigma rubrum 

 and P. fulvum very similar to that of Collema, and in this case also the archicarp 

 alone produces the ascogenous hyphae at a later period. Spermogonia and spermatia 

 are likewise present, but the union of the latter with the archicarp has not been cer- 

 tainly observed, perhaps owing to their extreme delicacy. Moreover the archicarp 

 here makes its appearance inside a delicate (pseudo-parenchymatous) hyphal coil pro- 

 duced at first as a new formation in the thallus, which may be termed the primordium of 

 the sporocarp, and from it the envelope-apparatus of the sporocarp is subsequently 

 developed under conditions of new formation and resorption. The archicarp is a long, 

 coiled row of many cells. In this respect it is like the archicarp of the Collemaceae, 

 and one extremity of it projects as in that group in the form of a trichogyne above 

 the surface of the thallus, while the lower coils are concealed in the primordium. Before 

 the formation of asci commences, these coils are found to be divided into portions 

 containing from one to several cells and distributed in the future hypothecium, and 

 from here they put out the ascogenous hyphae in the form of branches ; but the 

 portion which protrudes as the trichogyne perishes without taking any direct part 

 in the formation of asci. All these phenomena are exactly similar to those observed 

 in the Collemaceae, as will appear from the special description of a subsequent page, 

 with the exception of the union of the spermatia and the presence of the primordium 

 from the first concealing the archicarp, neither of which has yet been ascertained. 



4. The processes observed in Xylaria again are similar to those in Poly- 

 stigma. First the appearance of a delicate primordial hyphal coil in the thallus; 

 then inside that of a coiled row of large cells similar to the archicarp of Polystigma 

 (named by Ftiisting Woroniris hypha] ; finally of cell-groups distributed in the 

 hypothecium from which the asci sprout, while Woronin's hypha is to a great 

 extent at least disorganised and disappears. But a piece of Woronin's hypha 

 projecting from the primordium, a trichogyne, has not been observed, and there- 

 fore no visits of spermatia to it ; nor is there any proof of genetic connection 



