32 Fishery Board for Scotland. 



The 14lh vertebrae ia represented in fig. 138. A little bony boss is 

 present above and below the cone. A side view of vertebra 22 is 

 shown in fig. 144. The cones between the groups 15-17 and 18-19 

 are small, not exceeding 2 mm. in diameter. The former group, in 

 which the lines of fused and individual vertebra; could not be traced, 

 was cut longitudinally (fig. 143) A little double cone is seen to be 

 present between the component vertebrae. The vertebrae had been 

 normal up to a certain stage in the life of the fish, viz., when the 

 vertebra was between 2 and 3 mm. in diameter, i.e., the size of the 

 double cone. Thereafter a diseased condition of the joints had 

 supervened. The vertebra had grown no more in length. All its 

 increase had been in breadth. The ends of the vertebrae had 

 adhered. The line of fusion can be traced in the section, and along 

 it there are some little spaces. The size of the cone on the end of 

 the vertebra indicates the period when the disease attacked the 

 vertebra. It evidently attacked the median vertebrae first, there- 

 after, proceeding towards each extremity. In this way some of the 

 vertebrae would be attacked much later than others. Vertebrae 37 

 and 38 appeared to have fused recently. 



At first all the vertebrae would be movable Later on, as the 

 normal vertebras grew in length, it is probable that the joints 

 between the thin vertebrae would not all he moved in the action of 

 swimming. Some of them would probably tend to fuse. The 

 abnormal vertebras that remained movable have irregular, 

 roughened ends (e.g., fig. 136). In this case half of the cone only is 

 present, and the hilum is hardly traceable. The thin vertebra majr 

 be concave on one side and convex on the other (fig. 144). In the 

 unhealthy joints which are still movable there was a fleshy-like tissue 

 instead of the jelly mass present in the normal joint. 



The shortened vertebrae usually have their dorsal and haemal 

 spines connected by a bony plate. 



The neural and haemal spines of vertebrae 34 and 35 have been 

 broken and mended. 



Between some of the abnormal vertebras there were little tumour- 

 like swellings about 3 mm. in diameter. One tumour that issued 

 from between vertebrae 17 and 18 (tu., fig. 136) was brown in 

 colour. It had formed a depression in the bone. Tumours were 

 present in the neural canal attached, apparently, to the neural 

 sheath, which seemed to be thickened. The spinal cord did not 

 seem to be affected. 



I examined the joints of a humpty cod in the fresh condition. 

 There was onty a very small cone-mass of jelly, brownish in colour. 

 Under the microscope some little brown or opaque white bodies, 

 apparently stalked, were observed. The bodies had thick walls 

 (figs. 58 and 66). There was some other amber-coloured tissue 

 exhibiting a great quantity of minute corpuscles. 



Two hump-backed cod were mature. A male measuring 34* 

 inches (87 cm.) in length was ripe: a female 2 If inches (54 cm.) 

 was spent. The abnormal portion in both was short. In the 

 former it was over the kidney. This fish had a slight spinal curva- 

 ture also. Part of the kidney was much broken up. I found 

 therein colourless cysts varying in size from 07 mm. in diameter to 

 1-4 mm. in length. They in some cases showed a single chamber, 

 in others several chambers. Some of the cysts enclosed a vermiform 



