SEA-FISHERIES LABORATORY. 



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muscle bundles themselves. In text-fig. 1, A represents 

 the appearance of one of these larger nodular masses, 

 natural size, and B in the same figure represents the 

 appearance of one of the more diffuse growths. It will 

 be seen that in A the tumour does not affect the epidermis 

 and immediate subjacent layers, nor is the tumour 

 raised up above the level of the skin. The muscle bundles 



Text-Fig 1. Melanotic Sarcoma in the Skate. Hand sections of 

 part of the pectoral fin. Natural size. 



are pushed to each side, but it is evident that the 

 intrusive tissue, although it may have spread along the 

 connective tissue, intermuscular septa, has invaded the 

 substance of the muscles themselves. In the neighbour- 

 hood of these larger subcutaneous growths there may be 

 a slight infiltration of the muscles with black pigment. 

 This is not necessarily the growth of the sarcoma, but 

 may merely be due to the breaking down of the latter, 



