Convincing evidence as to the importance of the trichogyne in fungi was supposed, until lately, to be afforded by the presence and functional activity of that organ associated with spermogonia in a few Pyrenomycetes—in _Poronia_, _Gnomonia_ and _Polystigma_. _Poronia_ was examined by M. Dawson[636] who found that a trichogyne-like filament distinct from the vegetative hyphae rose from the neighbourhood of the ascogonial cells. It took an upward course towards the exterior, but there was no indication that it was ever receptive. In _Gnomonia erythrostoma_ and in _Polystigma rubrum_ spermogonia with spermatia—presumably male organs—are produced in abundance shortly before the ascosporous fruit is developed. The spermatia in both cases exhibit the characters of male cells, _i.e._ very little cytoplasm and a comparatively large nucleus that occupies most of the cell cavity, along with complete incapacity to germinate. Brooks[637] found in _Gnomonia_ that tufts of the so-called trichogynes originated near the ascogonial cells, but they were “mere continuations of ordinary vegetative hyphae belonging to the coil.” They are septate and reach the surface, and the tip-cell is longer than the others as in the lichen trichogyne. A somewhat similar arrangement is present in _Polystigma_, in which Blackman and Welsford[638] have proved that the filaments, considered as trichogynes by previous workers, are merely vegetative hyphae. A trichogyne-like structure is also present in _Capnodium_, one of the more primitive Pyrenomycetes, but it has no sexual significance. Lindau[639] in his paper on _Gyrophora_ suggested that the trichogyne in lichens acted as a “terebrator” or boring apparatus, of service to the deeply immersed carpogonium in enabling it to reach the surface. Van Tieghem[640] explained its presence on physiological grounds as necessary for respiration, a view also favoured by Zukal[641], while Wainio[642] and Steiner[643] see in it only an “end-hypha,” the vigorous growth of which is due to its connection with the well-nourished cells of the ascogonium. Lindau’s view has been rejected by succeeding writers: as has been already stated, it is the paraphyses that usually open the way outward for the apothecium. Van Tieghem’s theory has been considered more worthy of attention and both Dawson and Brooks incline to think that the projecting filaments described above may perform some service in respiration, even though primarily they may have functioned as sexual receptive organs. There is very little support to be drawn from fungi for the theory that the presence of a trichogyne necessarily entails fertilization by spermatia. Lichens in this connection must be judged as a class apart.