114 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
prevent one from concluding what its appearance must 
have been. I think necrosis has occurred in the central 
parts of the growth, and this was the cause of the injury. 
Irregular pigment spots, varying in diameter from 
about 3 to 6 mm., were scattered over the skin of the 
anterior part of the body. Dr. Roaf thought it possible 
that these might represent metastatic formations, and one 
such piece of skin was fixed for examination. But the 
tissue is apparently quite normal except for a greater 
development of the black pigment underlying the 
epidermis. It is difficult to say whether or not there is 
any indication in these pigment spots of a commencing 
generalisation of the sarcoma—possibly this may be their 
meaning. 
The liver was very soft, a condition apparently due 
to the formation of extensive lacunae among the hepatic 
tubules. The coloration is due to the deposition of 
melanin among the otherwise normal tissues. The pigment 
is present in groups of round bodies, each about twice the 
size of an hepatic cell. It is difficult to say now whether 
or not the pigment is deposited within hypertrophied 
hepatic cells, or whether it is contained in intrusive cells 
—probably the former is the true condition. 
The brain, muscles, cartilage and other organs, except 
the spleen and gills, were quite normal. The gills are 
deeply pigmented with melanin. 
The fully-developed tumour itself, and a small 
portion of its growing edge, were examined in section. 
Fig. 1, Pl. V, represents the general appearance of a 
thin section of the tumour, which has been stained in 
methyl-blue-eosin. Very little of its structure can be 
made out in such a preparation because of the density of 
the tissue and the deep pigmentation ; and it was necessary 
to decolourise the sections. The pigment is very stable, 
