ON STAINING FOR VITAMIN C IN TISSUES
Guinea-pig adrenals were stained for ascorbic acid. In the normal adrenal, staining was found in both cortex and medulla though with greatest density in the zona fasciculata. The stained scorbutic adrenal showed only a few granules.The mosses Mnium cuspidatum and Mnium affine contain ascorbic acid in appreciable amounts. Following staining, fine black granules could be seen in both species. The stain intensity of the granules roughly corresponded to their relative ascorbic acid content.Having satisfactorily established the validity of the staining solution by the above experiments the development of ascorbic acid in the rose hips of R. acicularis was followed throughout the summer. There was found to be some association between the ascorbic acid and chloroplasts. With increasing maturity there developed a gradual accumulation of fine granules in the cells of the tissue as well. These granules showed no apparent relationship to any formed elements in the cells. Staining densities roughly parallel ascorbic acid content.