1. 1. Cantor, H. & Boyse, E. A. J. exp. Med. 141, 1390–1399 (1975). 2. Bach, F. H. et al. Immun. Rev. 35, 76–96 (1977). 3. Wagner, H. & Rollinghoff, M. J. exp. Med. 148, 1523–1538 (1978). 4. Singer, A., Kruisbeek, A. M. & Andrysiak, P. M. J. Immun. 132, 2199–2209 (1984). 5. Guimezanes, A. & Schmitt–Verhulst, A.–M. Eur. J. Immun. 15, 1187–1191 (1985). 6. Sprent, J. & Schaefer, M. /. exp. Med. 162, 2068–2088 (1985). 7. Sprent, J., Schaefer, M., Lo, D. & Korngold, R. /. exp. Med. 163, 998–1011 (1986). 8. Dialynas, D. P. et al. J. Immun. 131, 2445–2451 (1983). 9. Dialynas, D. P. et al. Immun. Rev. 74, 29–56 (1983). 10. Wofsy, D., Mayes, D. C., Woodcock, J. & Seaman, W. E. / Immun. 135, 1698–1701 (1985). 11. Coulie, P. G., Coutelier, J–P., Uyttenhove, C., Lambotte, P. & Van Snick, J. Eur. J. Immun. 15,638–640(1985). 12. Titus, R. G., Ceredig, R., Cerottini, J–C. & Louis, J. A. J. Immun. 135, 2108–2114 (1985). 13. Waldor, M. K. et al. Science 227, 415–417 (1985). 14. Wofsy, D. & Seaman, W. E. J. exp. Med. 161, 378–391 (1985). 15. Fenner, F. Aust. J. exp. Biol. med. Sci. 25, 275–282 (1947). 16. Alien, A. M., Clarke, G. L., Ganaway, J. R., Lock, A. & Werner, R. M. Lab. Anim. Sci. 31, 599–608 (1981). 17. Wallace, G. D. & Buller, R. M. L. Lab. Anim. Sci. 35, 41–46 (1985). 18. O'Neill, H. C. & Blanden, R. V. Infect. Immun. 41, 1391–1394 (1983). 19. Blanden, R. V. /. exp. Med. 132, 1035–1054 (1970). 20. Blanden,, R. V. /. exp. Med. 133, 1074–1089 (1971). 21. Gardner, I., Bowera, N. A. & Blanden, R. V. Eur. J. Immun. 4, 63–67 (1974). 22. Gardner, I., Bowern, N. A. & Blanden, R. V. Eur. J. Immun. 4, 68–72 (1974). 23. O'Neill, H. C., Blanden, R. V. & O'Neill, T. J. Immunogenetics 18, 255–265 (1983). 24. Widmer, M. B. & Bach, F. H. Nature 294, 750–752 (1981). 25. Von Boehmer, H. & Turton, K. Eur. J. Immun. 13, 176–179 (1983). 26. Von Boehmer, H., Kisielow, S., Leiserson W. & Haas, W. J. Immun. 133, 59–64 (1984). 27. Moldwin, R. L., Lancki, D. W., Herold, K. C. & Fitch, F. W. /. exp. Med. 163, 1566–1582 (1986). 28. Sprent, J., Schaefer, M., Lo, D. & Korngold, R. Immun. Rev. 91, 195–218 (1986). 29. Morse, H. C. Ill et al. J. Immun. 122, 443–454 (1979). 30. Yeh, C.–J. G., Hsi, B.–L. & Faulk, W. P. J. Immun. Meth. 43, 269–27'5 (1981). 31. Mishell, R. I. & Dutton, R. W. /. exp. Med. 126, 423–442 (1967). 32. Buller, R. M. L. & Wallace, G. D. Lab. Anim. Sci. 35, 473–477 (1985).