1. Carleton, H. M. and Leach, E. H.Histological Technique, Oxford Univ. Press, 1938.
2. Chambers, R. and Hofler, K. “Micrurgical Studies on the Tonoplast ofAllium cepa,”Protoplasma, 1931,12, 338–55.
3. Conklin, E. G. .. “Cellular Differentiation,” inGeneral Cytology, Ed. E. V. Cowdry, 1925, 537–607.
4. Darlington, C. D...Recent Advances in Cytology, 1932, J. and A. Churchill, London.
5. Gatenby, J. B. and Cowdry, E. V.Bolles Lee’s Microtomist’s Vade Mecum, 1929, J. and A. Churchill, London.