The macroconidial septum of some dermatophyton species.

The septum of the macroconidium (MC) of dermatophytes was examined by light microscopy. Significant taxonomical differences between species have not been found. The septa seem to be three-layered, but only the middle layer can be considered a septum in the wall substance of two neighbouring chambers, impressed and completed by the septum. The septum verum originates from the middle layer of the three-layered MC wall or from its surface adjacent to the chamber wall. This type of septum is different from that described in Ascomycetes and other species. Light microscopic findings are insufficient to characterize the nature of the septal pore. The microscopic observation of the layers of the MC wall and of the septum may be disturbed by misleading optical phenomena.