204 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



The columnar cells are high and slender, and have their 

 nuclei at the extremities away from the cavity of the 

 cyst. Their free extremities are banded : a densely 

 staining zone forms the free edge of the cell, and then 

 next to this is a lightly staining zone. 



The external layer of the wall resembles that of the 

 thin-walled cysts already described, and next to this 

 is a layer composed mostly of smooth connective tissue 

 fibres. In this, however, there are numbers of unstriated 

 muscle fibres, all running in one direction. Between 

 this and the layer of columnar epithelium is a layer 

 consisting mainly of loose areolar tissue. Elastic fibres, 

 however, pass from the denser layer through this into 

 the interior of the villus-like structures. There are some 

 rather remarkable glandular bodies in this areolar layer : 

 these are represented by the darkly stippled patches ih 

 fig. 6, and they are also shown in fig. 11 as seen under 

 an immersion lens. They consist of groups of cells, 

 sometimes arranged irregularly, but as a rule grouped 

 round a small but most distinct lumen or cavity. The 

 cells are rather of the " eosinophilous " type, finely 

 granular in structure, and with small darkly staining 

 nuclei near their outer extremities. These glandular 

 bodies do not seem to be connected together, nor do they 

 open into the cavity of the cyst. 



Blood vessels are very few in either the thick- or 

 thin-walled cysts, but there are cavities in the thin- 

 walled bodies which are filled with small lymphocytes. 



The cysts do not, then, appear to resemble any 

 structures figured in pathological works. Tet they are 

 undoubted morbid growths. 



A Phycomycetous Fungus in a Mackerel (Scomber scomber). 



A mackerel caught by Mr. A. Scott off Walney 

 Island in July last, proves to have been infected by a 



