of the Fishery Board for Scotland. 



57 



below. There was no black pigment associated with the cyst, and the larva 

 within it was not so far advanced as those found in the whiting. I was 

 able to make out no definite characters. The cyst measured "75 X '62 mm. ; 

 it had a very thick rind. 



Injured Gadus callarias. 



The small cod referred to on page 61 had lost the whole of its tail (fig. 

 41). The wound had, however, healed up, and the fish was well nourished. 



On May 5th, 1902, a cod was got in the trawl in the Moray Firth which 

 had some of the opercular and branchiostegal bones exposed. The branchios- 

 tegal membrane had been torn, and one ray projected, with the greater part 

 of its length bare of flesh. It had a thick crop of Zoophytes and stalked 

 infusors growing on it (fig. 42 ; s. indicates the outeide of the skin of the 

 fish). The bone was 2 \ inches long, and If inch was exposed. The surface 

 of the bone was decaying, and could be scraped off as a white powder. 

 Several small nudibranchs were found among the Zoophytes. 



Tumours from the Cod (Gadus callarias). (Figs. 45, 52.) 



The larger tumour was sent to the Laboratory on 26th February, 1907. 

 It, along with a number of other abnormal specimens, have been generously 

 supplied by Mr. Angus. It had apparently been attached to the gullet. 

 A mark had been observed on the wall of the abdomen, against which it 

 pressed. It weighed 2 lbs., and measured 6| inches by 5| inches by 

 3| inches (fig. 45). It was fibrous, composed of laminae, concentric in 

 parts, with radiating fibres. It was supplied with large blood vessels. 

 An opening led into a narrow slit-like cavity, which is shown exposed in 

 fig. 52. The surface of this cavity was in part white and clean ; the 

 remaining portions were discoloured, and had a dried substance adhering. 

 One large vessel was discharging a thick whitish fluid into the cavity. 



Prince* described a tumour from a cod. It was evidently a connective 

 tissue capsule formed around a foreign body in the peri-visceral cavity ; this 

 foreign mass, like a large fragment of undigested food, lying outside the 

 walls of the alimentary canal. 



A tumour obtained on 18th February was attached to the wall of the 

 stomach, within an inch of the pylorus. It is egg-shaped (fig. 57) ; it 

 measured 45 cm. in length, 2"8 cm. in breadth, and it rose to a height of 

 2*5 cm. above the outside surface of the stomach wall. It is solid, and quite 

 smooth externally, with fine blood-vessels showing as little red streaks. 



The wall of the stomach is composed of two external layers of muscles 

 and a thick white fibroid layer which forms the internal surface. The 

 muscle-layers run at right angles to each other ; they are bound tightly 

 together. The thick white fibroid layer is almost as thick as the muscle- 

 layers, and is separated from them by connective tissue. The muscles are 

 inserted into the fibroid layer. The latter shows its surface marked all over 

 with closely-set dimples. 



The tumour seems to be composed almost entirely of muscle and fibrous 

 tissue binding the muscle together. It has apparently been formed by the 

 great local growth of the inner layer of muscles. The outer layer of muscles 

 forms an outer coat to the tumour. External to the muscle there is a thin 

 fibrous skin. The tumour is separated from the cavity of the stomach by 

 the fibroid layer alone. Fig. 63 shows the inner surface of the stomach at 

 the part. The position of the tumour is indicated by a dotted line. That 

 part of the stomach wall is smooth, but there are ridges round it. A 



* " On an Internal Tumour from the Abdomen of a Cod." Tenth Animal Report of 

 the Fishery Board for Scotland for 1891, Pt. III., p. 324. 1892. 



