Report on Diseases and Abnormalities in Fishes. 27 



shrivelled, and measured 12 5-13 7 mm. in diameter. Some were 

 still spherical. There was no signs of development in the ova. 

 The ovary was small, and when it reached me it was ruptured. At 

 first it appeared to be a case where the stomach or the gut had been 

 ruptured and had permitted eggs which had been eaten by the fish 

 to pass out into the abdominal cavity. The ovary had some old 

 unspawned eggs in it: one measured 13 mm. in diameter. The 

 ovarian ridges had very small immature eggs. This was evidently 

 a case where the ripe ovary had been ruptured, and the eggs had 

 escaped into the abdominal cavity. The stomach of the fish contained 

 two or three small sandeels. 



Bone in the Stomach of a. Salmon. — A salmon was found dead in 

 fresh water about 12 miles up from the mouth of the Helmsdale. 

 A bone was found sticking in the wall of the stomach, which 

 had been perforated. Great inflammation had been set up, 

 apparently causing the death of the fish. Mr. W. L. Calderwood 

 kindly forwarded the bone to me. It is evidently part of the lower 

 jaw of a fish. It is shown in natural size in fig. 148. The bone is 

 a dentary, and it has been broken. It is membranous and remark- 

 ably thin. It resembles the dentary of a herring, but it is longer 

 and more fragile. The teeth are very small for the size of the jaw. 

 The upper ramus of the bone is longer than the lower. While it 

 resembles a little the corresponding bone of a pike, the teeth are too 

 small for that species. I have not been able to determine the 

 species to which it belongs. 



Bone in the Lip of a Skate. — A serrated spine, apparently one of 

 the spines of the dorsal fin of a Gurnard (Trigla), was found broken 

 off and embedded in the side of a skate's mouth. 



Discoloured Flesh of Salmon. 



Mr. J. Hector, salmon merchant, Aberdeen, kindly sent to the 

 Laboratory, on April 24, 1912, a salmon which had, on cutting, 

 been found to be discoloured in the flesh. The fish weighed 17 lb. 

 It had been gutted, but as it had a fairly prominent kype on the 

 lower jaw it was judged to be a*male. The fish was in excellent 

 condition. From the middle of the length of the abdomen back- 

 wards the flesh was in increasing extent coloured red instead of pink. 

 Fig. 107 shows the extent of the reel colouration (r.) at about the 

 middle of the abdomen. In front of the first dorsal fin the red region 

 extended well on both sides of the vertebral column (fig. 108). 

 A little behind the pelvic fins a somewhat similar condition was 

 found. The muscles in the wall of the abdomen were brownish. 

 At the beginning of the anal fin the whole section was dark red. 



The red colouration of the flesh is consequent on braises received 

 before death. In this case there was no recently-made bruise 

 visible. The fatty fin, however, was deformed (fig. 110). It was 

 hollow, the inside tissue had disappeared, and two apertures (ap.) 

 gave access to the cavity. On the ventral edge of the body, just 

 behind the anal fin, there was a wound which was almost quite 

 healed. The anal fin is inflamed a little ; the membrane is red- 

 coloured. I could not find that in either of the two former cases 

 the wound had penetrated aeeper than the skin. The wound in the 

 fatty fin was discharging a little yet. I examined some of the 



