SEA-FISHERIES LABORATORY. 195 
Two Plaice with external tumours. 
In October, 1908, two plaice were sent to the 
laboratory by the Board of Agriculture and Fisheries. 
There were large and prominent tumours on the skin of 
each. In view of the great interest that would attach to 
the discovery of cases of malignant tumours in fishes taken 
from the open sea, some considerable attention was paid 
to the nature of the structures in question. It proved, 
however, that the growths were not malignant; never- 
theless, they may be worthy of detailed description. 
M—tnrewAl) Granulation Tissue Tumour. 
The fish was a mature female 49 cm. in length. The 
stomach and intestine were empty. ‘The viscera were, 
apparently, normal, and the fish was in good condition. 
Fig. 2, Pl. IV, is a photograph, nearly natural size, 
of the tumour on the skin of this plaice. It was situated 
on the ocular side, about half-way between the anus and 
the root of the tail; about one-fourth of it was dorsal to 
the lateral line. The growth was roughly circular in 
shape, about 3d mm. in diameter, and raised up above the 
general level of the skin about 5to10 mm. The skin was 
broken all round the periphery of the growth, and raised 
to nearly the upper level of the latter. The substance 
composing the tumour was dead white in colour, and 
consisted of dense fibrous tissue. It was slightly 
excavated in the centre, as shown in the photograph. 
Perhaps part of it had been rubbed away in handling the 
fish. “There was no pus tissue. | 
A large area of skin immediately round the tumour 
was abnormally pigmented, being dense black in colour. 
This is not very well shown in the photograph. This 
patch of skin stood out very distinctly from the rest, 
shading away quite sharply into the surrounding pigment. 
