96 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



in edible fish do not inhabit the human body. Even if they 

 did, the cooking process would generally destroy them. Such 

 fish should not be condemned. 



It cannot be said that the malignant tumours, that is 

 " cancers," of fish are likely to prejudice the health of the 

 consumer. The common-sense way of dealing with such fish 

 is to cut out the part containing the tumour and then to use 

 the rest. 



In one case part of a halibut containing " a filthy black 

 substance " was sent to the laboratory. The black substance 

 was a melanotic sarcoma. In some cases these melanotic 

 tumours are multiple and their appearance is forbidding. 

 Rupture of a small tumour of this kind would spoil the appear- 

 ance of the fish, and no customer seeing such would be likely 

 to buy. But if there is only a single tumour that can be cut 

 away, this should be done and the rest of the fish retained 

 for sale. 



A tumour that is malignant and spreads, or sets up 

 secondary tumours, is likely to affect the general condition 

 of the fish. So also with the rather rare cases where the flesh 

 of a fish is extensively invaded by parasite worms, or protozoa. 

 In such cases toxic products may possibly diffuse out from 

 the disordered tissues round the parasites, or from the necrosing 

 (or breaking- down) tumour. These toxic products may enter 

 the blood stream, with the result that the health of the fish 

 suffers, and its flesh becomes emaciated. A fish in such condition 

 is easily recognised by the inspectors, and it ought, in my 

 opinion, to be condemned just as if it were partially decomposed 

 owing to imperfect preservation. 



All such specimens are of very considerable scientific 

 interest, and are always fully investigated in the laboratory. 

 Such diseased fishes are always thankfully received, and 

 inspectors and others are requested to forward them whenever 

 found. 



