Abstract:Structural changes in the seutellar parenchyma and epithelial cells of oats during the first 3 days of germination were followed by electron microscopy. The seutellar parenchyma cells contain more protein bodies than the epithelial cells, otherwise the general fine structures of the two types of cells arc quite similar: When the seed starts to germinate the protein bodies change into vacuoles and the proteins inside the protein bodies gradually disappear. Spherosomes are in abundance ill the seutcllar cells of the dry seed. Few disappeared during germination. Other cellular organelles, such as the mitochondria, endoplasmie reticulum, plastids, Golgi apparatus and glyoxysomes are scarcely seen in the seutellar cells of the dry seed. They become more obvious and easily recognizable after germination. In the dry seed, the walls of the epithelial cell that abut the endospernl show a two layered structure, consisted of an inner and outer layer. The outer layer becomes hydrolysed during seed germination, but the inner layer remains intact. The scutetlar epithelial cells are known for their ability to secret enzymes ute and absorb nutrients from the endosperm. But in the fine structural studies we have not been able to locate any specific strurcture that could be related to their known functions of enzyme secretion and nutrient absorption.