Beattie. — On tlie Anatomy of tli-c Bed Cod. IT 



of the organ. The auricle occupies the dorsal part, and the 

 ventricle the ventral part. 



The air-bladder extends throughout the whole length of 

 the abdominal cavity, and lies below the vertebral column, 

 from which it is separated throughout the greater part of its 

 length by the middle kidney. At its posterior end it hes just 

 below the rather thicker posterior kidney, and at its anterior 

 end it is bounded above by the lymphatic glands. At_ its 

 anterior end the air-bladder gives off two cornua, which, 

 passing outwards and slightly upwards, end in a blunt ex- 

 tremity just posterior to the opercular bone. 



Peritoneum : This consists of the usual parietal layer 

 lining the body- cavity, and visceral layer reflected over the 

 viscera. In the anterior two-thix'ds of the abdominal cavity, 

 the peritoneum, which chere lies on the outer side of the liver, 

 is extremely delicate, and is closely attached to the liver, while 

 in the posteiior third, especially on the right side (the right 

 lobe of the liver not extending to the posterior end of the 

 abdominal cavity), it is quite free, and consequently can be 

 easily made out. On the ventral face of the air-bladder in the 

 middle line the two layers pass into one another, and from this 

 point pass ventrally the various mesenteric attachments of 

 the viscera, which are in strict agreement with those given for 

 Gadus morrhua in Professor Parker's " Zootomy." There 

 are various invaginations of the visceral layer, which form 

 peritoneal pouches for the various organs. One on each side 

 passes between the liver and the stomach and mtestine. On 

 the right side the stomach and some of the folds of the in- 

 testine and gall-bladder are separated by a second pouch, and 

 each gonad is enclosed in a separate pouch. 



The Air-oladdcr. — The air-bladder covers the whole of the 

 dorsal wall of the abdomen, the peritoneal lining of which is 

 reflected over its ventral surface. The dorsal wall of this 

 bladder is, especially in the middle and anterior regions, much 

 thinner than the lateral and ventral walls. 



The air-bladder passes from the posterior part of the abdo- 

 minal cavity forwards right to the anterior part as a regular 

 oval body. It theii diverges dorsad, and to the right and left, 

 forming a right and a left cornu. 



These cornua pass outwards and forwards until they reach 

 almost the exterior (being separated from the outside merely 

 by a thin layer of skin), just below the operculum in front of 

 the dorsal end of the shoulder-girdle. They end blindly, and 

 their anterior walls lie close against the posterior part of the 

 cranium. The anterior face of the bladder, or, more strictly, of 

 its cornua, towards the middle line is much thickened. This 

 is especially the case at two points v/here a thick button-like 

 body is seen. These button-like bodies are found to fit against 



