1. Gibbons, R. A., and Glover, F. A., in Flow Properties of Blood and Other Biological Systems, edit. by Copley, A. L., and Stainsby, G., 234 (Pergamon Press, London, 1960).
2. Gibbons, R. A., Nature, 184, 610 (1959).
3. Harvey, C., and Jackson, M. H., Lancet, ii, 723 (1948).