Report on Diseases and Abnormalities in Fishes. 31 



Deformed Fishes. 



Humpty Cod. — Hump-backed cod are not uncommon. They are 

 found among those captured in the North Sea and at Faroe : they are 

 said not to occur among Iceland fish. It has also been maintained that 

 humpty cod are more common in the catches of the inshore boats : 

 they are very rarely got by the deep-water boats. Some were, how- 

 ever, got 50 miles off Aberdeen. 



The cod is shortened. While the anterior and posterior portions of 

 the body are normal, the middle part of the trunk has increased in 

 dorso- ventral extent and decreased in length (fig. 128). The body 

 narrows abruptly behind the abdomen (figs. 104 and 128). The 

 abnormality occurs in the vertebral column. The humpty fish is 

 bilaterally symmetrical. 



When the vertebral column of such a fish is cleaned the inter- 

 mediate vertebrae are found to be individually shortened and also 

 to be fused together in groups. The column is thickened there, and 

 when the fish is being split this part catches the knife. The fish 

 represented in fig. 128 measured 44 cm. in length. It had been 

 gutted. The abdominal cavity extended posteriorly as far as the 

 first third of the first anal fin. Little white balls, resembling the 

 cj^sts in the eye of Gadus esmarki were present in the sclerotic. 

 Concretions were found at different parts of the skull. 



The vertebral column is shown in fig. 149. It consisted of 52 

 vertebrae. The following analysis divides the vertebrae into normal 

 and abnormal, and the latter into independent and fused vertebrae. 



Veatebne, 1-5 normal. 



,, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, abnormal, independent. 



,, 15, 16, 17, abnormal, fused. 



,, 18, 19, ,, ,, Vertebra 19 bears the first haemal 



arch . 

 20, 21, 

 ,, 22, ,, independent. 



23-29, ,, fused. 



,, 30, 31, slightly abnormal, independent. 



,, 32, 33, 34, ,, ,, fused, broadened. 



,, 35, 36, normal. 



,, 37, 38, 39, slightly abnormal, fused, broadened. The drawino- 



wrongly shows Vertebras 37-40 



fused. 

 ,, 40, 41. ,, ,, fused. The drawing wrongly 



shows Vertebrae 41 and 42 



fused. 

 ,, 42-52 normal. 



Vertebrae 6 and 7 are slightly abnormal (fig. 146). They are 

 shorter and broader than Nos. 4 and 5. The joint between these 

 vertebrae is open at the edges. The anterior end of No. 7 is seen in 

 fig. 141. The cone (en.) shows the extent of the attachment to the 

 adjacent vertebra. Its abnormally small size is seen when it is 

 compared with the large normal cone of the 5th vertebra (fig. 142). 

 In the normal vertebra each end is a deep hollow cone, extending 

 across the whole breath of the vertebra (en. fig, 151). The 

 adjacent vertebrae are bound together round the rims. The double 

 cone in the joint is filled with a clear colourless jelly material. 



The cone in the end of the abnormal vertebrae gradually becomes 

 smaller and the vertebrae thinner as one proceeds along the column. 



