120 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



ON CERTAIN PARASITES, DISEASED AND 

 ABNORMAL CONDITIONS OF FISHES. 



By Jas. Johnstone, D.Sc. 



1. A Fungoid Infection of Plaice 120 



2. Tetrarhynchid Larvae in the Plaice ... ... ... ... ... 121 



3. Degenerate Cestode larvae in the muscles of a Hake ... ... 121 



4. On the Occurrence of a " Birth-Pore " in Anthobothrium musteli 



(van Beneden) ... ... ... ... ... ... ... 123 



5. Sarcomatous Tumours in the mouth of a Cod ... ... ... 126 



6. On the Occurrence of an additional Pectoral Fin in Raia m.aculata 127 



7. Sarcomatous Tumours on the Head of a Conger ... ... ... 128 



1. Fungoid Infection of Plaice. 



Parts of the organs of two plaice that had died in the 

 Port Erin spawning pond were sent to me in September of 

 1916 by Mr. H. C. Chadwick. The liver, spleen, kidney, 

 and the peritoneum covering the intestine of these fish contained 

 small whitish nodules about one to two millimetres in longest 

 diameter. Smaller cyst-like bodies were also seen in the 

 substance of the liver. On dissecting out some of these 

 larger nodules, staining and flattening out beneath a cover- 

 glass it was seen that each was a fungus-colony, or growth. 

 Fig. 2 represents a part of such a nodule as seen beneath a 

 low power. It is a mycelium with sporangium-like bodies. 



Fig. 1 represents part of a transverse section through a 

 part of the intestine, and shows that the tissues of the latter 

 are invaded by the fungus. The latter is represented in the 

 figure by the black bodies. They are principally present in 

 the submucosa, which is rather thicker than normally is the 

 case, but some are also present in the tissue between the two 

 layers of muscular tissue. Traces of mycelium are also to be 

 seen in the section. 



The affection, so far as the fungus is concerned, is similar, 

 probably identical, with that described by me in 1905* in 

 * Report Lancashire Sea- Fish. Lab. for 1905, p. 179. PI. XVI. 



