160 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



Anderson* has recently described a very similar 

 disease among whiting and plaice from Bay of Nigg, 

 Aberdeen. He gives the following description of the ulcers 

 on the plaice: — " They commenced in paling and 

 desquamating spots, spreading rapidly to form large 

 ulcerated areas, often one to two inches in diameter. 

 The edges of the ulcers were deeply undermined, the base 

 often extending down to the muscular tissue. ... The 

 base of the ulcers often presented a very injected appear- 

 ance." This would apply equally well to the Port Erin 

 fish. 



The disease described by Anderson was apparently 

 more virulent than the present one, though its virulence 

 seems to have decreased towards the end of the period he 

 mentions ; thus during September and October 187 dead 

 plaice were removed from the pond, while from that until 

 December 26th only 13 more were found. 



Anderson regards the disease as some form of 

 septicaemic poisoning, possibly caused by sewage-borne 

 organisms. The pathogenic organism seems to have been 

 the Staphylococcus pyogenes aureus, which was obtained 

 from all the superficial lesions examined and from the 

 blood in most cases. In this respect, therefore, it differs 

 from the disease now described. 



The Port Erin disease cannot be due to sewage 

 pollution, as the water is remarkably pure, and the fish 

 are obtained from areas where there can be no question 

 of pollution. These septicaemic conditions may be due 

 to various organisms acting on fish which are under 

 abnormal conditions. As regards fresh-water fish, 

 Ceresole* has described a bacillus causing ulcerative 

 septicaemia in gold-fish (Carrassius auratus). 



* 28th Ann. Eep. Fish. Bd. Scotland, Pt. Ill, 1911. 

 t Zentr. fur Bakt. und Parasitenkunde, Bd. 28, 1900. 



