1. Abdon, N. and Richter, W.: J. exp. Med. 130, 141 (1969).
2. Adler, W. H, Takiguchi, T., Marsh, B. and Smith, R. T.: J. exp. Med. 131, 1049 (1970).
3. Affolter, J.: Schweiz, med. Wschr. 63, 881 (1933).
4. Albuquerque, L. R., Perini, A. and Mota, I.: Int. Arch. Allergy 41, 797 (1971).
5. Amos, E. and Lachmann, P. J.: Immunology 18, 269 (1970).