Spindle membrane in meiosis of pollen mother cells of Tradescantia and in mitosis of endosperm cells of Zephyranthes.

In the previous paper (Wada, Nagao and Awasawa 1963), we have demonstrated the presence of spindle membrane in fixed preparations of root tip cells in Vicia faba and Allium cepa. These materials are most familiar in the laboratory for observations of mitosis in somatic cells and their mitotic figures are described in text-books of cytology as a standard type of somatic cell division. In this paper, the presence of a spindle membrane will be demonstrated in the meiosis of pollen mother cells of Tradescantia and in the mitosis of endosperm cells of Zephyranthes in fixed preparations. The former cells are used commonly for observations of meiotic figures by means of aceto carmine smear method and the mitosis of endosperm cells is recently draw ing attention as plant material available for in vivo observations, especially for chromosome movement under phase contrast microscope (Bajer 1957).