1. Albrecht, O., thesis, Univ. Leipzig (1932), cited in ref. 4.
2. Webster, W., Austral. Vet. J., 8, 199 (1932).
3. Barker, C. A. V., Canad. J. Comp. Med., 20, No. 2 (1956).
4. Nieberle, K., and Cohrs, P., Lehrbuch der Speziellen Pathologischen Anatomie der Haustiere, edit. by Fischer (Jena, Germany, 1949).
5. Jubb, K. V. F., and Kennedy, P. C., Pathology of Domestic Animals, 1 (Academic Press, 1963).