282 G. H. DREW. 



the fibrous tissue cells were observable. Sections of the softer peripheral 

 j)art of the tumour (Fig. 3) showed irregular loosely packed strands of 

 fibrous tissue containing a few elongated nuclei, and large numbers 

 of the small round cells, described above, often occurring in small 

 aggregations between the strands and fibrils of the fibrous tissue 

 stroma. No definite blood-vessels were present, and blood spaces were 

 rare. Superficially this portion of the growth was entirely covered by 

 a single layer of squamous epithelial cells continuous with the 

 epidermis, but there was nothing in this covering corresponding to 

 the other layers of the skin, and no denticles or mucous glands were 

 present. 



It would thus appear that the tumour had been originally a simple 

 fibroma arising from the perichondrium of one of the fin rays, and that 

 later this had taken on a sarcomatous type, and had proliferated 

 freely. Considering the very poor blood supply to the peripheral part 

 of the tumour, the fact that this portion should have become of a 

 distinctly sarcomatous nature, its evident free proliferation, and the 

 absence of necrosis, is remarkable. 



AN ENDOTHELIOMA OF AN EEL (CONGEE VULGAEIS). 



This tumour was found on an eel caught at Plymouth. The fish was 

 an immature female, about four feet long, and appeared in good 

 condition. 



The growth consisted of a nearly spherical mass in the region of the 

 basi-hyal; it was about 1 inch in diameter and protruded about 

 1;^ inches from the level of the skin. The tumour was of a whitish 

 colour, but in parts was somewhat haemorrhagic ; the surface was 

 rough and irregular, with, in places, minute pits lined with thickened 

 epidermis. The skin was not continuous over the surface of the growth, 

 but gradually thinned away at its margin until the junction of skin 

 and tumour became indistinguishable and inseparable. The outer 

 portion of the growth was moderately soft, but it felt as though there 

 was a hard central part which was continuous with the basi-hyal ; the 

 arrangement suggested a considerable outgrowth of thickening of the 

 basi-hyal in an anterior direction, and that this outgrowth had pene- 

 trated through the skin and become closely adherent to it at the margin. 

 An incision made along a diameter of the tumour showed a central 

 bone-like core, apparently formed by an outgrowth of the basi-hyal^ 

 and small areas of highly vascular tissue interspersed among patches of 

 white fibrous tissue, in some of which deposition of lime salts was 

 taking place. Other areas appeared semicartilaginous and some seemed 

 myxomatous. 



