Electron Microscope Observations on the Leaf of Azolla imbricata Nakai

In the electron micrographs of the leaf in Azolla imbricata, the following could be observed.1. In the young cell wall, plasmodesmata are well observed.2. In the leaf cells, Golgi apparatus and endoplasmic reticulum not so many are observed as in cells of roots or root hairs.3. Immature plastids in the leaf cells show similar structures to those observed in root cells or the root hair ones, while mature plastids show well differentiated grana-lamellae similar to the plastid common in higher plants.4. It is concluded that the plastids found in Azolla roots or root hairs have an ability to change to chloroplasts.