In 1952, Perner found spherical Cytoplasmic granules in onion which he thought to be new organellae and called spherosomes"2%. He reported that onion spherosomes were spherical, 0.6-1.4,u in diameter, refracted light strongly, appeared in the mitochondrial fraction on differential centrifugation, were basophilic and were rich in lipid and cytochrome oxidase. Subsequently, spherosomes have been found in many plants3-6'. However, the cytochemistry of spherosomes has been little studied and their

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... ossible functions as organellae are not yet clear. The purpose of the present study is to determine whether spherosomes in Hydrodictyon reticulatum are organellae or not. Material and Methods The Cytoplasmic granules of Hydrodictyon reticulatum were studied using a light microscope under bright and dark ground illumination. Culture: Hydrodictyon reticulatum was cultured in Pocoek solution7' without addition of soil decoction with alternate 12 hours periods, under artificial light (5,500 lux) and in the dark at 25°. Every two weeks, the culture medium was renewed. Vital staining: Cells of Hydrodictyon reticulatum were stained by 10 minute's immersion in 0.005% neutral red (Gri bler) dissolved in McIlvaine's buffer solution (pH 7.0). To study the effect of pH on vital staining with neutral red, Sorensen's buffer (above pH 7.0) and Walpole's buffer (pH 2.7-6.5) solutions were used. Vital staining was also done in a 0.005% solution of Janus green B (Fisher).