20 Fishery Board for Scotland. 



appeared to be quite healed. In the depression there was some 

 gelatinous material enclosing what appeared to be a few sand grains 

 and some crystals. The latter effervesced in dilute sulphuric acid 

 (H 2 S0 4 ). The ends of two ribs projected a little way through the 

 skin. 



The swim-bladder was normally distended with gas. On 

 opening it, evidence of its having been diseased were apparent. 

 The surface of the rete mirabile was enclosed in a thin skin, under 

 which ihere was a layer of solidified yellow matter. The latter was 

 gelatinous-like, not a true tissue. It interdigitated between the 

 folds of the rete. A soft tuberculated mass was removed from 

 between the iolds. In it there were several white cysts. Similar 

 opaque cysts were observed in the rete. The swim-bladder had been 

 the seat of disease, which had been relieved by perforation of the 

 wall of the body. The nerves on the inside of the wall of the 

 abdomen were infested with trematode cysts. 



The hole in the shoulder of the fish was in the place in which one 

 would puncture a cod which had a swim-bladder abnormal^ 

 distended. Sometimes a cod living in the aquarium at the 

 Laboratory has its swim-bladder so distended that it floats helpless 

 on the surface of the water. If the swim-bladder be punctured by 

 a needle, and the gas allowed to escape, the fish is able to take its 

 normal position in the water. 



Gurlej'" mentions the case of a Oachis merlangus affected with 

 complete atrophy of the tail muscles, the tail being composed of 

 nothing but skin and bone. Not the slightest trace of muscular 

 tissue remained. The junction of the normal and atrophied tissue 

 was abrupt, and was situated at the root of the tail. Woodhead 

 described caseous tumours in the muscles of the Hake (Merluccius 

 vulgaris). 



l)rouin de Bouville says that the disease Furunculosis salmonicida 

 observed in Trutta fario consists in tumours which raise the skin 

 at certain points on the body. At first the tumour encloses a 

 yellowish-white caseous substance, which finally resolves itself into 

 a blood-stained pus. The tumour eventually bursts, making ulcerous 

 wounds, which give out a reddish discharge. He considers that the 

 disease is of a bacterial origin, due to Bacillus salmonicida, Emmerich 

 and Weibel. 



Saithe. — A large tumour was present on both sides of the tail. It 

 was firmly attached by gristle to the vertebral column. The haemal 

 arches of three vertebrae were broken. The disease appeared to 

 have arisen within the haemal arches. In the haemal arches 

 occupied by the tumour there was no sign of the caudal vein. Both 

 anterior and posterior to the tumour the red caudal vein was visible. 

 The end of the vein on the anterior side was filled with coagulated 

 blood. The fish had been boiled before examination. This 

 appeared to be a lymph tumour. 



A large saithe had a tumour which projected from the head in a 

 huge spherical mass* The skin over the tumour was inflamed, and 

 it seemed as if ready to open. Inside the tumour was a pasty mass, 

 yellow and pink in colour. The matter was evil-smelling, and it 

 showed here and there a little blood. It seems to have been a lymph 

 tumour. 



* Presented by Mr. G. Allan. 



