1. ARNOTT, H. A. and SMITH, K. M. (1967) J. Ultrastruct. Res. 19, 173–95.
2. BAWDEN, F. C. (1964) Plant Viruses and Virus Disease. 4th ed. New York: Ronald Press Co.
3. BAWDEN, F. C. and KASSANIS, B. (1941) Ann. appl. Biol. 28, 107.
4. BEALE, H. PURDY. (1937) Contr. Boyce Thompson Inst. Pl. Res. 8, 415–31.
5. BLACK, L. M., MORGAN, C. and WYCKOFF, R. W. G. (1950) Proc. SOC. Exptl. Bid. Med. 73, 119.