34 Fishery Board for Scotland. 



inches long, and the fishers asserted thai <hey occasionally met with 

 it in the coal-fish (Gadus virens). He suggested as the possible 

 cause, debility in the vascular system, in consequence of which the 

 bones lose their phosphate of lime, become soft and spongy, then 

 absorbed, and the joints become thickened and enlarged — in short, 

 rickety, as found in the human subject. 



Several examples of Humpty haddocks are preserved in the 

 Laboratory. 



Hump-backed Hake* (Merluccius vulgaris). A hump-backed 

 hake measuring 24 inches (60 cm.) in length had the hump in the 

 post-anal body. It extended close up to the root of the tail. The 

 tail was normal. There was a series of little tumours, measuring 

 up to 7 mm. across, between several of the vertebrae of the abnormal 

 part. They had a definite cyst wall, and they were located mostly 

 between the vertebral spines, dorsal or ventral. The contents con- 

 sisted of dried material, in which I was able to make out no definite 

 structure. 



Cobbold recorded a hunch-back trout. He said : " We have here 

 an extreme abrogation of the spinal column resulting from the 

 coalescense of numerous vertebral centra." 



Hyrtl stated that " the number of coalesced vertebrae is from 2 

 to 6 , and this synostosis takes place more frequently in the tail than 

 in the trunk of the fish. The diminution of the flexibility of the 

 fish, due to the abolition of the inter-vertebral articulation, is 

 obviated by the fact that the confluent vertebra? are not longer than 

 one and a slight fraction of a non-coalesced one. The synostosis is 

 not due to pathological deformities, there being no callosity present 

 to suggest a mechanical injury, and no deposits of calcareous matter 

 to induce us to regard the synostosis as a senile metamorphosis. 

 The inter-vertebral foramina appear never to be perfectly obliterated, 

 although they are exceedingly diminished in size. The synostosis 

 is, without doubt, of a physiological character, and it must take 

 place early in life, when the length of the bodies of the vertebras is 

 so short that 2, 3, 4, or 5 such lengths are equal to the length of a 

 single vertebra of a fully-grown-up individual. When the increase 

 in length is stopped the increase in circumference continues, as in 

 non-synostosed vertebral bodies." 



Howes drew attention to the fact that Hyrtl later described a 

 case in the cod, in which 6 co-ossified vertebra? occupied a greater 

 area than the two which preceded them. The author regarded the 

 deformity as congenital. 



Ritchie records a hump-backed trout. He considered that the 

 malformation did not arise from the fusion of little groups of 

 vertebra?. He regarded each group as a true centrum having an 

 abnormal number of spines. If this condition actually occurs it is 

 not always the case, as the longitudinal section of the fused mass has 

 shown the different centra distinctly marked off. 



Spinal Curvature. 



This abnormality j? comparatively common in the cod. A 

 number of instances of its occurrence in large cod have come under 



* Presented by Mr Napier, Aberdeen. 



