SEA-FISHERIES LABORATORY. 119 
part of the fish—the possible metastases—this layer of 
pigment is developed to a greater extent than elsewhere. 
The epidermis contains numerous goblet mucous cells, 
represented by the small elliptical white spots in the 
figure. 
Directly beneath the epidermis, and piercing the 
latter, are the scutes of the skin: a part of the flattened 
base of one of these structures is represented in the figure. 
The dermis, forming the lower layer of the integument 
consists of one or more layers of coarse connective tissue, 
and some areolar connective tissue. The superficial layer 
of the dermis consists of very coarse fibres running parallel 
to the surface of the skin. These fibres are wavy, are not 
very long, and are divided into short bundles separated 
by vertical connective tissue dissepiments. There are also 
fibres running perpendicularly to the surface of the skin, 
but the horizontal series is the more highly developed. 
The scutes are embedded in this dermal connective tissue. 
The superficial layer rests on a thin layer of fine fibres, 
and the deepest of the coarser fibres of the superficial layer 
of the dermis stain more deeply than the others. Beneath 
this fibrous ‘‘ basement membrane’’ is another layer of 
coarse connective tissue fibres; then a thin layer of areolar 
tissue; and then another layer of coarse fibres. Beneath 
this again is another layer of coarse areolar tissue con- 
taining blood vessels, and the sensory canals occupy this 
layer of the skin. Deepest of all may be yet another layer 
of coarse fibres, and then we come upon the muscles of the 
body. Two of these muscle fibres, cut transversely, are 
represented in the figure. I do not suppose that this 
arrangement of the layers of the dermis is quite constant 
in every part of the skin of the fish, but it is that 
arrangement present in the vicinity of the tumour. 
Fig. 2, Pl. IV, represents the proliferating edge of 
