V. R. RAJAGOPALAN & V. R. GOPALAKRISHNAN                 307

reaction between Past. pseudotuberculosis rodentium sera and mouse pasteurella
antigen, similar to that observed by Smillie (loc. cit), seems curious but not
unaccountable.

                                       SUMMARY

An outbreak of rodent septicaemia in white mice, maintained for experi-
mental purposes at the Imperial Veterinary Research Institute, Mukteswar, is
described.

The causal agent—a member of the Pasteurella group was subjected to a
detailed study. It was found to be culturally, morphologically and biochemi-
cally very closely related to or probably identical with Pasteurella muricida
[Meyer and Batchelder, 1926].

A comparative serological study of the organism with some strains of
Pasteurella in our stock and their relationship are also discussed.

This appears to be the first record in India of the occurrence of Pasteurella
muricida as the cause of an epizootic among rodents.

                        REFERENCES
Cornelius, J. T. (1929). J. Path. Bact. 32, 355
Hueppe, F. (1886). Berl. Klin. Wsck. 23, 776
Jones, F. S. (1921). J. A. V. M. A. 60, 271
Lal, R. B. (1927). Amer. J. Hyg. 7, 561
Meyer, K. F. and Batchelder, A. P. (1926). J. Inf. Dis. 39, 386
Roderick, L. M. (1922). J. Inf. Dis. 31, 313
Schutze, H. (1929). Syst. Bact. Med. Res. Coun. 4, 474
Smillie, W. G. (1920). J. Inf. Dis. 27, 378
Tanaka, A. (1926).      ibid,      38, 421
Topley, W. W. C. and Wilson, G. S. (1937). The Principles of Bact. & Immunity, 2nd
Ed.
Yusef, H. S. (1935). J. Path. Bact. 41, 203