Conidiogenesis in the synnematous hyphomycete Stilbella annulata (Berk
. and M.A. Curtis) Seifert is initially enteroblastic with basipetally
retrogressive secession and enteroblastic conidiogenous cell prolifer
ation, where each conidiogenous cell apparently produces a maximum of
seven conidia. The first conidium is produced enteroblastically. Chain
s of synnemata are formed as a result of two processes: (a) from conid
ia which may not normally be seceded and then germinate into hyphae, o
r be normally seceded and germinate above the conidiogenous locus with
no physical attachment to the underlying structure, except the mucila
ge in which the conidia germinate; (b) the continuation of normal vege
tative growth after the full complement of conidia has been produced.
Ultrastructurally, the marginal hyphae contained no septa, which expla
ined the non-abscission of these structures. Morphologically they are
therefore modified hyphae and not analogous to conidiogenous cells.