Re‐organization of Fine Structure During Rehydration of Desiccated Leaves of Xerophyta Villosa

SUMMARY Air‐dry viable leaves of Xerophyta villosa , fixed in non‐aqueous fixatives, show disorganization of the cytoplasm and loss of cristae, grana and thylakoids, but retention of intact double membranes around plastids and of intact nuclei. Some reorganization of cell fine structure takes place while the leaves are rehydrating: cristae reappear in the mitochondria and numerous spherical vesicles in the plastids first swell, flatten to discs, and associate at their rims to form the thylakoid system and, following full rehydration, grana. Reformation of starch grains in the rehydrated tissue appears to precede the renewal of net photosynthesis.