SEA-FISHERIES LABORATORY. 201 



clumped masses of organisms there is a diffuse pink 

 staining, as if some substance had been excreted by the 

 bacilli into the surrounding tissues, and this had taken 

 the stain in the same way as the organisms themselves. 



The lesion is then obviously the result of an 

 infective disorder, and the general similarity of structure 

 of the nodules with those produced in warm-blooded 

 animals by the tubercle bacillus justifies us, I think, in 

 describing it as a case of piscine tuberculosis. The 

 pigmentation of the skin is a frequent feature in lesions 

 of many kinds in fishes : it is to be associated with 

 inflammatory processes, and has no particular signi- 

 ficance. Piscine tubercle is of course known,* but, so 

 far as I can find, only from fresh-water species, and it is 

 of interest to find so typical a condition in a fish living 

 in the open, and not at all likely to have become infected 

 by land drainage. 



The detailed bacteriology of these lesions is described 

 by Dr. Alexander on page 219. 



Ovarian Cysts in Angler (Lophius piscatorius). 



A female Angler, about 5 feet in length, was sent 

 to the Laboratory last May by Captain Wignall. On 

 dissecting it with a view to the discovery of worm 

 parasites, it was noticed that the wall of the ovaries 

 contained rounded cyst-like bodies. The fish was a spent 

 one : the ovaries were quite empty, and their wall was 

 represented by a germinal epithelium containing 

 practically only one layer of very small ova. The cysts 

 were usually attached to the external surface of this : 

 they were of various sizes, the largest being about 2\ by 

 1^ cms. in diameter, and the smallest being about 

 \ cm. Their shapes varied, some being almost spherical, 



* SeeHofer, Handbuch der Fischkrankheiten. Stuttgart, 1906. 



