1. Cleland, W. P. (1956). J. thorac. Surg., 32, 813.
2. Desforges, G., Gibbons, G., and Strieder, J. W. (1954). Ibid., 28, 636.
3. Inada, K., Sat6, A., KishimotB, S., and Tanabe, G. (1954). Ibid., 27, 503.
4. Jackson, C. A., and McCann, J. J. (1956). Tubercle (Lond.), 37, 36.
5. Lucas, B. G. B., and Cleland, W. P. (1950). Thorax, 5, 248.