SEA-FISHERIES LABORATORY. 197 
the skin is thickened and frayed out. By far the greater 
part of this thickened part of the integument is formed 
by the connective tissue bundles of the dermis, which 
spread out (in section) in a fan-like manner. Between 
these cuticular connective tissue bundles is a quantity of 
dense, wavy, fine, fibrous tissue; and towards the surface 
of the growth this intercalated tissue becomes pre- 
dominant and is exposed. The core of the growth is 
formed by a mass of the same kind of dense fibrous tissue, 
and, as shown in the figure, this extends downwards to 
near the vertebral column. ‘The arrangement of the 
muscle bundles of the trunk is roughly indicated in the 
figure, and it will be seen that hardly any of the substance 
of the tumour is made up of muscular tissue. Here and 
there indeed, scattered muscle bundles, or even isolated 
fibres, can be seen in stained sections, but these are not 
at all prominent, and they are present there because the 
foreign fibrous tissue has grown out from between the 
muscle bundles, and forced the latter apart. 
The whole is probably a healing tissue—a conclu- 
sion made by Prof. Annett, of the Department of 
Comparative Pathology at Liverpool University. Probably 
the fish had received some injury: if so it must have been 
considerable, and a comparatively large amount of tissue 
must have been actually removed. In a fish like the 
plaice, comparatively small wounds heal quickly, and 
leave but little trace. Even the wound made by passing 
the silver wire, used in “ marking ” those fishes, through 
the body near the dorsal fin, hardly ever becomes greater, 
never suppurates, and even after two years during which 
period the wire, bone button, and brass label have been 
attached to the fish, there is hardly any enlargement of 
the hole through which the wire passes. Fishes like 
plaice, flounders, halibut, turbot and brill are occasionally 
