12 Fishery Board for Scotland. 



Diseased Kidney. 



Tusk (Brosmius brosme). — The fish was in good condition. The 

 outward form of the disease was a large irregular mass, measuring 3 

 inches (7*5 cm.) long by about 2 inches (5 cm.) wide by 1 inch (2 - 5 

 cm.) thick (fig. 44). It was dark coloured, and projected into the 

 abdominal cavity on the left side of the ovary. It was covered with a 

 thin skin (the skin of the kidney), which, through its blood supply, was 

 reddish-coloured in parts. This tumour-like mass was simply a huge 

 blood clot which had been formed by haemorrhage, probably from the 

 caudal vein. On the outside of the clot there was a whitish sub- 

 stance, a sort of dried pus. 



The hind part of the kidney was diseased. The haemal arch was 

 filled with diseased tissue and round yellow bodies. The urinary 

 bladder was large and normal. It was evident that none of the 

 products of the disease had issued by the urethra. 



The capsule of the tumour, i.e., the skin of the kidney, is spotted 

 all over with little brown oval bodies, which are also present in the 

 mesentery. 



The hind end of the kidney is a hard, nodulated, brown mass, in 

 which there is a mat-like mass of soft fibrous tissue. This apparently 

 consists of the vessels and urinary tubules, the tissue of the kidney 

 having been destroyed. The vessels are covered with brown bodies 

 (shown shaded in the figures, sp., figs. 39, 46, 50). They are of 

 various sizes. One measured '2 by "15 mm., while others were only 

 •1 mm. in diameter. They appear to be situated in little vessels. 

 Some of the tubules end in swollen extremities, in which a coiled 

 tube may be made out (co., fig. 50). On one of the vessels a small 

 glandular-looking swelling was observed (g., fig. 39). In addition 

 to the brown bodies, there are opaque yellow cysts in the diseased 

 kidnej^. One measured 3 mm. in diameter (c, fig. 50). It 

 contained dry solid granular matter. 



In the abdominal cavity, in the angle formed by the junction of 

 the rectum with the ventral wall of the abdomen, there was in the 

 mesentery a mass of cysts, some of which were 2 mm. long. They 

 were amber-coloured, and had a glistening external coat. Certain of 

 these cysts were also on the inside of the wall of the rectum. Some 

 nematodes were observed alongside the cysts. The little brown or 

 yellow bodies found in the kidney may not be the cause of the 

 disease. The disease had evidently been long-standing. It had 

 resulted in the decay of the tissue of the kidney, and in very exten- 

 sive haemorrhage, probably from the large vessels that lie close to 

 the kidney. 



Cod (Gadus callarias). — A disease similar to that found in the 

 tusk was present in a codling. A large tumour which projected 

 from the hind part of the roof of the abdominal cavity was 

 a diseased and swollen part of the kidney. It was covered by the 

 tough skin of the swim-bladder. Attached to the vessels of the 

 kidney there were numbers of tubers (x., fig. 49). The tuber was 

 generally pear-shaped, and was united to the vessel by a narrow 

 stalk. The tuber marked x. measured 1*7 by 1*5 mm. Most, if not 

 all, of the kidney was infected. Instead of the brown bodies found 

 in the tusk, there were here little white opaque bodies, which 



