1. Baker, J. R...Quart. J. Micr. Sci., 1944,85, 1.
2. —————.. Ibid., 1949,90, 293.
3. Bourne, A. G...Austr. J. exp. Biol. Med. Sci., 1934,12, 123.
4. —————..Cytology and Cell Physiology, Clarendon Press, Oxford, 1942.
5. Bowen, R. H...Z. Zellforsch, 1928,6, 689.