The ultr~tstructure of the scutellum and the aleurone layer has been examined in seeds of Nordal barley following malting for 0, 30, 72, 120 and 162 hours at 15 ~ Thick sections from the seeds were stained with Calcofluor White M2R New and examined in the light microscope to determine the extent of cell wall degradation in the endosperm.The changes in the scutellar parenchyma cells include degradation of the protein bodies and the appearance of vacuoles and prominent amyloplasts. The analysis of a serially sectioned epithelial cell from the scutellum 72 hours after the start of malting revealed a large number of Golgi apparatuses, preferentially located near the cell wall. It is suggew that the presence and location of the Golgi apparatuses are related to enzyme secretion. Following malting for 72 hours or more, the epithelial cells contain lomasomes and membrane aggregates, termed membrane bodies. The analysis indicated that lomasomes originate from the membrane bodies and are involved in the growth of the cell walls of the epithelium. Organelles indicating cellular activity, i.e., rough endoplasmic reticulum, mitochondria and Golgi apparatuses, first appear in the epithelial cells of the scutellum, and later in the cells of the aleurone layer. Furthermore, the degradation of the endosperm starts in the vicinity of the scutellum as judged by the ca|cofiuor staining. Therefore, it is concluded that the scuteltar epithelium provides the enzymes during the initial degradation of the endosperm. In seeds malted for 162 hours, aleurone ceils with a cytoplasmic organisation indicative of active metabolism are located in the embryo part of the seed, whereas aleurone ceils adjacent to unmodified endosperm in the distal end of the same seed show little or no structural sign of activity.

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