SEA-FISHERIES LABORATORY. 115 



Fig. 2. An un encapsulated sarcomatous nodule among 

 adipose tissue near the ventral fins. Fibrous 

 tissue becoming replaced by fat cells. The 

 sarcoma is invading the coarser fibrous tissue 

 between the fat cells. There is no trace of a 

 capsule. Mag. about 25 dia. 



Fig. 3. Edge of a sarcomatous nodule showing the break- 

 down of the capsule. The nodule is surrounded 

 by muscle fibres, and has at most of its 

 periphery a fibrous capsule. At the place 

 shown the capsule disappears, and the sarco- 

 matous tissue is infiltrating the surrounding 

 muscle-tissue. The stippled area represents 

 closely-crowded ellipsoidal or spherical cells. 

 See also PL III, fig. 1. The diameter of the 

 whole field is about 2 mm. 



Fig. 4. The growing edge of a sarcomatous nodule 

 infiltrating dense fibrous tissue. To the right is 

 the typical sarcoma ; to the left is dense fibrous 

 tissue with coarse bundles. Degenerating 

 muscle fibres are represented above. Diameter 

 of the whole field about 2 mm. 



Fig. 5. A small part of the tumour shown in fig. 4, 

 where the sarcoma is typically developed. 

 Small, round cells; larger irregularly rounded 

 cells; some spindle cells. Cell debris, and 

 melanin granules. Apochromatic lens. 



Fig. 6. A small part of the growing edge of the tumour 

 shown in fig. 4. Small, round cells infiltrating 

 connective tissue. Apochromatic lens. 



Fig. 7. A small part of the dense, fibrous tissue which 

 lies to the left in fig. 4. It is well away from 

 the growing margin of the tumour, but some 

 small ellipsoidal and round cells are contained 



