Report on Diseases and Abnormalities in Fishes. 25 



seems in many cases to cause an ulcer on the skin of a fish, but the 

 possibility that the ulcers arise on uninjured areas is not excluded. 



Cod — Pimpled Skin. 



The fish* measured 3 feet 6 inches (105 cm.) in length. The 

 skin and fins were covered with pimples. The pimples extended 

 upon the clavicle inside the lip of the gill-chamber and all over the 

 inside of the mouth. Thej were cysts either completely sunk in the 

 derma or projecting from the lower surface of the derma into the 

 connective tissue, separating 1 it from the muscles. I did not see 

 any cyst in the muscle. 



The pimples measured up to 2 mm. in diameter. They are 

 irregularly-shaped areas, reddish or purplish, showing through the 

 white skin (fig. 132). Some of them showed little external scars, 

 as if they had been punctured. On pressing one a little mass of 

 thick stiff matter was forced out. Some have ulcer-like craters (n.) 

 on them. The region appeared to be inflamed. 



The spleen is remarkable, being spotted with dendritic white 

 growths (fig. 129). The growths are shown of natural size in the 

 drawing. The outside of the gut and liver is infected with great 

 quantities of nematodes, most of which are coiled up. 



Pinkish Flesh of a Codling. 



The flesh of a codling was pinkish coloured. It was slightly 

 stiff er to cut than the normally coloured fish. 



Disease of the Eye — Pterygium. 



One of the cod, which exhibited the deformity of the spinal 

 curvature (p. 35), had a diseased eye. It was a white opaque 

 patch (w.) over part of the pupil (fig. 170). It was in parts 

 coloured red by blood-vessels that ran over it from the bulbar con- 

 junctiva. The pterygium is a changed part of the cornea. Blood- 

 vessels can also be seen in a part of the conjunctiva that is still trans- 

 lucent, viz., at tr. The e} T eball was spotted with yellowish blotches. 



The normal cornea can be dissected into two layers, both of which 

 are translucent. The inner layer is tough, gristly. Fig. 172 shows 

 a section through the cataract. One half, the outer, of the cornea is 

 diseased (d.), while the inner (n.) is translucent. 



Perforation of the Gut. 



Foreign Bodies in tlte Abdominal Cavity of Fishes. 



A number of cases where some of the food of the fish had escaped 

 from the alimentary tract into the abdominal cavity, to become 

 encysted there, were recorded in a previous paper. In the majority 

 of instances the food was sandeels (Ammodytes). It was difficult to 

 understand how these fishes had managed to perforate the wall of 

 the stomach or gut. Barrett had suggested that the sandeel had 



* Presented by Mr. Rose. 



