SEA-FISHERIES LABORATORY. 129 



the latter has been pulled a little to one side in making 

 the dissection for the figure. The nerve itself is partly 

 atrophied. It is greatly flattened out, and near the 

 bulbus it consists of relatively few fibres. It cannot be 

 traced into the bulbus, and it is evidently undergoing 

 degeneration, although the imperfect fixation of the 

 specimen did not allow of this condition being minutely 

 studied. 



Underneath the tumour, and between the latter and the 

 floor of the orbit, was a small flattened body, fatty and 

 semi-transparent in appearance, with a little black 

 pigment. This is indicated in fig. 7. It is apparently 

 the remains of the recessus orbitalis. 



Nature of the Tumour. 



The fish had been preserved in weak formalin before 

 being sent to me, and the fixation of the tumour was far 

 from being all that could be desired. Nevertheless, 

 almost all details of its minute structure could be deter- 

 mined, and I think there is little doubt as to its nature. 

 It was surrounded by a very loose investment of fibrous 

 tissue, and under a low power a complete transverse 

 section showed what appeared to be a number of bundles 

 of connective tissue radiating out from one main point 

 on the margin of the growth, with two other series of 

 bundles radiating out from adjacent parts of the margin. 

 Outside the tumour were the sections of the muscle 

 bundles, and that of the optic nerve. 



The greater part of the substance of the tumour is 

 made up of loose, delicate, fibrous, connective or elastic 

 tissue bundles, running mainly parallel to each other, and 

 forming what might be called the trabeculae or frame- 

 work of a stroma, consisting of a very delicate reticulum. 

 But towards the external part of the tumour these fibres 



