a. Phase-contrast micrograph of a hypha growing on a slide culture.

b. Phase-contrast micrograph of the same hypha shown in fig. 8a after aldehyde fixation. Figs. 8a & 8b are shown at the same magnification. Scale bar = 10 µm.

c. & d. Electron micrographs of near median thin sections of the same hypha shown in fig. 8b. The cluster of vesicles in the apex has a distinct central region with fewer vesicles (enlargement). This region corresponds to the phase-light central region of the Spitzenkörper seen in fig. 8b. Scale bar = 1 µm.