The Macroconidium Appendage in Microsporum Gypseum

SUMMARY

The macroconidial appendages in Microsporum gypseum are borne by a group of macroconidia whose frequency in one strain varies with age and growth conditions of the culture. Most frequently the appendages are borne singly on the apical cell; infrequently they are borne singly on the basal cell, in pairs on the apical cell, or one at each end of the macroconidium. Regardless of number and position, the appendages are slender, filamentous, aseptate, typically simple but rarely branched, containing 1–5 nuclei. They are formed after the macroconidia have separated from the conidiophores. In contrast to the germ tubes which are produced by each macroconidial cell, the appendages are of finer width and determinate growth, and their formation is confined to one or both of the terminal cells of the macroconidium.