636 MR. G. E. BULLEX OX 



The condition termed by Hofer * " Keratoglobus," ■?'. e. out- 

 M^ard bulging of the cornea away from the pupil, did not afiect 

 either eye, the lenses retaining their normal position. 



Blindness, therefore, in this instance was due apjjarently to 

 mortification and bacterial lesions of the integument of the head 

 passing over the eye attendant upon perforation of the cornea- 

 epithel. 



Hofer t remai'ks : " In the case of a fish weakened by disease, 

 or in a dying condition, the organs of sight are deeply sunk 

 in their orbits, whereas in a healthy fish the eyes somewhat 

 protrude." In the present example this condition was wholly 

 apparent, the eyes presenting the flabby appearance to be seen in 

 a fish some hours after death. 



It is highly probable, therefore, that perforation of the integu- 

 ment above the cornea, resulting in blindness, was largely due, 

 in the present instance, to the susceptibility of the fish, already 

 weakened by graver organic disease, to injury ; and that incipient 

 corneal opacitis may sometimes be taken as a diagnostic of other 

 disorders. 



2. Corneal Opacitis in a Greater Weever 

 (Trachinus draco). 



The chief difference between the condition of the eyes in the 

 present example and that of the Conger Eel already described, 

 lay in the fact that apparently no lesion of the cornea-epithel 

 appeared to have taken place. The subject under consideration 

 had lived for some years in the tanks at Biighton, and had 

 attained the considerable measurement of 15| inches. In this 

 case partial blindness onlj- had come about at the time when the 

 specimen was examined. The left eye was less affected than 

 the right, this showing a more or less evenly distributed film of 

 dimness, as if the specimen had been immersed for a short time 

 in weak formalin. The right eye, however, not only showed 

 distinct spots of necrosis unevenly distributed throughout the 

 surface of the cornea, but there was also a pronounced " kerato- 

 giobe." With reference to this latter feature, it may heie be 

 remarked that a gathering of aqueous humour in front of the 

 pupil, causing the cornea to bulge outward to a considerable 

 extent, may occur, doubtless as the result of concx;ssion, in fish 

 the eyes of which are otherwise ajjparently unaffected. At the 

 Brighton Aquarium occasionally numbers of a shoal of mackerel 

 may be observed with both eyes proti-uding in this way, but 

 their undoubted lack of efiectunl vision appears in no way to 

 interfere with their ca.pability for maintaining position in a 

 moving shoal. But it is a noticeable fact that they appear 

 much thinner than their fellows consequent upon a more limited 



* Op.cH. p. 293. 



t Op. cit. p. 290. The translations adhere as nearly as possible to the ori\;inal 

 te.xt. 



