Abstract: In Citrus grandis (L.) Osbeck, calls in the inner epidermis and subepidermal layers of carpels divided and formed the primordium of the juice sac which grew into columnar structure. There were mefistem-likecell clusters at the apex and meristem-like cell columns at the centre of file columnar structure. These ceilswere polygonal, each with a big nucleus surrounded by dense cytoplasm. The meristem-like cell colunm,which was absent in the stalk, rail longitudinaly through the centre of the columnar structure. It differentiatednear the stalk 7 weeks after anthesis. Two and a half months after anthesis, miniature of juice sac was formed.Juice sat, consisted of 4 zones, viz, epidermis, subepidermal cell zone, elongated cell zone and juice cell zone. The granulation process of juice sac included four stages. 1. The stage of healthy juice sac: At this stage the juice sac was fulfilled with juice and the sac appeared transparent. The subepidemal cells were col]enchymatuus with thichened comers. Death of pmtoplasts occurred in individual parenchyma cells. 2. Stage ofgelatination. The juice sac was transparent and filled with gelatinous juice. The collenchyma cell wall of the snbepidennal cell were completely thickened. Some cell walls in some juice sacs were lignified. 3. Stage of granulation. A portion of, if not the whole, juice sac is milky white. Walls of more cells in four zones are thickened and liguified. The walls of more cells in the four zones were thickened and lignified. 4. Late granu-lation stage: The juice sac was yellowish white in color, partly hardened and partly atrophied giving the sac inan irregular contour. Most cells of the hardened portion were lignified and most cells of the atrophied portion were dead and became oppressed. Eventually, healthy juice sac reduced, starch in the juice sac reduced and oil drops increased with the prolongation of storage time of fruits.

Key words: Citrus grandis, Juice sac, Differentiation, Granulation, Anatomy