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A FISH DISEASE FROM GEORGE'S RIVER. 



By R. Greig Smith, M.Sc, Macleay Bacteriologist to thk 

 Society. 



In the middle of August there was received from the Fisheries 

 Department the carcase of a bream which had been found float- 

 ing, in a dying condition, on the surface of George's River, a few 

 miles south-west of Sydney. The epidermis showed several 

 slightly hemorrhagic patches. The lateral blood vessels and 

 adjacent portions of the muscles were congested; the liver was 

 mottled and pulpy; the peritoneal cavity contained cheesy masses. 

 The stomach was much congested and contained a reddish viscid 

 fluid. The intestine was slightly congested near the anus, and 

 contained a dark bile-coloured fluid. The other organs were 

 apparently normal, and the muscles and alimentary canal were 

 found to be free from parasites. 



In the bacteriological investigation, plate cultures were made 

 with media which had been inoculated with the several parts of 

 the carcase. The muscles were proved to be sterile, while the 

 heart blood, the spleen, and the liver contained three organisms. 

 The first of these was a gelatine-liquefying fluorescent bacterium 

 (Bact. jiuorescens), which was not investigated further. The 

 second was a rather large bacterium, which slowly liquefied 

 gelatine and exhibited bipolar staining. A pure culture of this 

 organism was distributed in normal saline, and a few drops of the 

 suspension was injected into the muscles of two carp. Beyond 

 showing a scar at the point of inoculation, these were unaffected 

 and were apparently healthy after a month's observation. The 

 organism was not investigated further. 



The third organism was a smaller bacterium which rapidly 

 peptonised gelatine and stained bipolarly. It occurred in 



