1. Tomasi, jun., T. B., and Bienenstock, J., Adv. Immunol., 9, 1 (1968).
2. Thompson, R. A., Asquith, P., and Cooke, W. T., Lancet, ii, 517 (1969).
3. Newcomb, R. W., Normansell, D., and Stanworth, D. R., J. Immunol, 101, 905 (1968).
4. Avrameas, S., Taudou, B., and Chullon, S., Immunochemistry, 6, 67 (1969).
5. Rowe, D. S., McGregor, I. A., Smith, S. J., Hall, P., and Williams, K., Clin. Exp. Immunol., 3, 63 (1968).