G34 MR. G. E. BULLEX OX 



41. On some Cases of Blindness in Marine Fislies. 

 By G. E. BuLLEN, the Hertfordshire Museum, St. Albans'^. 



[Received April 24, 1913 : Read May 20, 1913.] 



Of recent years considerable attention has been given by 

 numerous ichthyojoathologists and iish-culturists to the sporozoic 

 and bacterial diseases affecting those species of fish which in a 

 live state form an article of commerce. 



The important work of Hofer t, and the Monograph now 

 appearing from th6 pen of de Drouin de Bouville J, are perhaps 

 two of the best known contributions of a general character 

 upon the subject. There are, moreover, numerous more or less 

 important works upon those organisms giving rise to disease : the 

 Myxosporidia, for example, have received considerable notice 

 from such investigators as Balbiani §, Thelohaii |i, Doflein ^, 

 and Gurley **, to quote but a few of the authors upon the 

 subject. 



Work which has been performed, even within the past decade, 

 upon the bacterial aspect of fish diseases is of too extensive a 

 character to be cited, however briefly, here. The same applies 

 to Saprophytic and other fungoid growths attendant upon 

 bacterial lesions. 



The investigations of J. Hulme Patterson and certain others 

 upon Salmon disease are well known and important contributions 

 to economic science in this respect. But with the exception 

 of certain papers by G. H. Drew and Patterson's findings, so 

 far as they apply to Salmon installed in sea-water, most of 

 the literature dealing with disease in marine fishes is confined 

 almost entirely to the oecology of pathogenic organisms. For, 

 whereas there is no inconsiderable amount of the literature 

 directed solely to the pathology of freshwater fishes, there is 

 at present a remarkable paucity dealing with those of marine 

 ha,bitat. 



The present paper, therefore, is put forward largely with a 

 view to associating the pathological aspect of certain forms of 

 eye diseases observed in marine fishes with those already 

 described, in more or less general terms, in the case of freshwater 

 species. 



* Communicated by John Hopkinson, F.L.S., F.Z.S. 



t ' Handbuch der Pischki-aiikheiten.' 



X ' Les Maladies des Poissons d'eau douce d'Europe.' 



§ ' Lemons sur les Spovozoaives,' Paris, 1884, etc. 



II " Recherches sur les Myxosporidies," Bull. Soc. France et Belgique, ser. 4, vol. v. 

 Paris 1894. etc. 



% 'Die Protozoen als Parasiten und Kraukheit Serrigers,' Jena, 1901. "Studien 

 zur Naturgeschichte der Protozoen," Zoologische Jalirb. xi. 1889, etc. 



** " Myxosporidia, etc." Rep. U.S. Commissioner for Fish and Fisheries, 1892. 

 Washington, 1894. 



