196 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
When the fish was received the colouring of the ocelli on 
the rest of the skin was distinct and normal. 
Directly underneath the growth thus described, and 
on the blind side of the fish, was a healed scar. This was 
indicated by an indistinct line, on either side of which 
was an area of skin devoid of scales. 
The tissues of the fish, muscles, liver, kidney and 
blood were examined for the presence of parasites; but 
when I had first the opportunity of seeing them, these 
parts were in a very bad state of preservation. It is 
perhaps inevitable, but none the less unfortunate, that 
such interesting specimens as this are almost always in 
Fie. 17. Plaice with tumour. Transverse hand section 
of part of the fish through the tumour. Nearly natural 
size. 
such a state, when received, that methods of exact 
histological investigation cannot be applied. ‘There was, 
however, no indication of the invasion of the plaice by 
any obvious internal parasite capable of withstanding 
imperfect preservation. 
Fig. 17 represents the appearance of a hand ‘section 
made through the middle of the tumour, and it will be 
seen that the greater part of the substance of this is 
composed of the greatly altered integument. All round 
the periphery of the growth, and extending towards the 
centre for about one-third of the diameter of the tumour, 
