Abstract: In the course of a study of the nuclear behaviour in a few species of Allium, we have observed various forms of crystals appearing in the cells of the leaf sheath and scales at different developmental stages. When the crystals first appear in the cells of the growing leaf sheath and scales, they are few in number and very small in size. With the organs concerned gradually becoming mature and senescent, the crystals not only increase in size and number but also vary in forms. For example, in addition to the most numerous column-like crystals, various other forms of single crystals and different types of druses also occur. Moreover, a tetragonal one may form on a druse of columnal crystals or a small round crystal is often observed on a columnal one. In a few cases, a group of small angular crystals is left behind in the place of the nucleus, while the later disappeared. Microchemical tests indicate that the nature of the well-formed crystals in the cytoplasm is evidently calcium oxalate. In the cells of the senescent leaf sheath and scales, the existence of plasmodesmata of a mixture of nuclear material and cytoplasm, as is evidenced by staining with acetocarmine, is clearly discernible. In the nuclei of some cells there are different numbers of unstained bodies and the chromatic material has apparently diminished. The release of achromatic material from the nucleus into the cytoplasm has also been observed in rare cases. These phenomena together with the deposition of crystals in the cytoplasm seem to facilitate the intercellular movement of the protoplasm by which the organic materials may be transported from the senescent organ to the inner growing one. This is an additional support to the view advanced in a previous paper (Lou, Wu et al., 1956).