Conidiogenesis in Endophragmiella.

The three new species of Endophragmiella described above display the same distinctive kind of conidiogenesis and origin of the successive proliferations as that found in the type species of this genus, E. pallescens Sutton (1973). Because this kind of proliferation has not hitherto been described in this genus a note of explanation is added here.

Conidiophores terminate in a conidiogenous cell which produces a terminal blastic conidium. Conidium secession occurs through a break in the wall of the conidiogenous cell below the level of the septum which delimits the conidium. This results in a frill at the base of the freed conidium and an open end at the apex of the remains of the conidiogenous cell. The penultimate cell now proliferates, by the extension of its distal septum. into the old conidiogenous cell and extends to various distances beyond its open end. The circular base of the proliferated septum finally appears is an inwardly projecting ring and the wall of the old conidiogenous cell persists as a sheath around the basal part of the proliferation. A single septum, occasionally more than one, is laid down in the proliferation thus delimiting a new terminal conidiogenous cell which then produces a terminal blastic conidium. The conidium secedes and the process is repeated. The result is a conidiophore sheathed toward the apex by the remains of the wall of successive conidiogenous cells. Within the conidiophore the circular rings at the level of the base of each sheath indicate the location of the septa which have proliferated.

In E. hymenochaeticola proliferations are described as sympodial as well as percurrent. It must he pointed out that. although the final appearance of the conidiophore may indicate a sympodial extension in relation to the scar left by the previous conidium. each sympodial proliferation has arisen from the basal septum of the conidiogenous cell; thereafter. failing to burst percurrently through the constricted apex of the conidiogenous cell, it makes its exit by rupturing the lateral wall. thus giving the appearance of a sympodial extension