Caseous Tumours found in the Muscles of the Hake. 463 



dark mass, which, shining through the pale muscle, renders 

 one point considerably darker than the surrounding tissue. 

 On section through the middle of this dark point, a cavity 

 half-an-inch in diameter is found. This is bounded by a 

 narrow zone of fibrous-looking tissue, which forms the 

 wall of the cavity, and intervenes between it and the 

 surrounding muscular tissue. This zone is translucent and 

 grey, without a tinge of the yellow observed in the muscles. 

 Within the cavity and attached, apparently only at a single 

 point, is a firm nodular mass of about the consistency of 

 beeswax. It is much browner than the surrounding tissues, 

 and running through it are deep brown streaks, almost like 

 old blood pigment stains. There is no fibrillation of the 

 mass, which breaks down irregularly, and has no definite line 

 of fracture. In some of the smaller pieces of muscle, similar 

 cavities and nodules are seen ; they are much smaller ; the 

 nodules are not so deeply stained, are attached almost con- 

 tinuously to the walls of the cavity, and are not quite so 

 brittle. 



On making a microscopic examination of the tissue which 

 lies outside the fibrous-looking lining of the cavity, the 

 following appearances may be distinguished. The striped 

 muscular fibres first attract one's attention, as they seem to 

 have undergone a peculiar vitreous degeneration at irregular 

 intervals along their whole length. I say at irregular 

 intervals, but perhaps it would be better to say that in some 

 of the fibres the vitreous patches appear at regular intervals 

 along their course, whilst in others, the whole of the 

 muscular elements have become transformed into this peculiar 

 material. 



Wherever this change has occurred the fibres are fractured 

 irregularly, usually at right angles to the longitudinal axis 

 of the muscle (PL XXIIL, Fig. 2). Nearer the cavity the 

 muscle fibres are also markedly atrophied (Fig. 1, d, e)\ 

 they do not measure more than one-fourth of the diameter 

 of the normal fibres. Between the atrophied and degenerated 

 fibres in this position there is an increase in the quantity 

 of connective tissue, which is made up of small round and 

 slightly elongated cells, with a few fibrils and older connec- 



