BY. W. SAVILLE-KENT, F.L.S, 59 



with salt, and more especially in the case of coarse fish such as 

 roach, dace, pike and carp has been long known to be a fairly- 

 successful remedy, but there is no doubt, and more especially 

 in the case of Salmonidee that the immersion of the diseased 

 fish in sea water works a yet more effectual cure. At the 

 instance of Professor Huxley and as recorded in his paper just 

 quoted, both salmon and sea-trout affected by the salmon 

 disease were confined in coops in the estuary of the 

 Tweed at Berwick in the year 1882. The fish, on being trans- 

 mitted to him after a short treatment, were found on careful 

 examination being made, by means of sections prepared for 

 the microscope, to be entirely cured of the disease for which 

 they had been treated. The subject of provision being made 

 for the similar treatment of special fish, such as the salmon 

 under cultivation at the Salmon Ponds, is well worth consider- 

 ation. At a comparatively small cost, tanks or baths of salt 

 water transported in casks from the mouth of the Derwent, 

 might be fitted up at the ponds for the temporary immersion 

 of the affected fish. Or arrangements might be made 

 when the fish are so few in number and of such value, for 

 their transport after breeding operations to salt-water ponds 

 or enclosures that might with facility be constructed in the 

 Derwent estuary. By the adoption of such a system, in 

 point of fact, a solution would be arrived at of the problem 

 of rearing salmon to maturity, and to their normal size and 

 quality, while still retaining them under artificial cultivation, 

 and by such means, in fact, a breeding stock of the species 

 might possibly be permanently maintained. 



Before leaving the subject of the fungus disease, I propose 

 to make a few remarks upon its bearings with relation to fish 

 other than the cultivated or acclimatised Salmonidse, and 

 with regard to the as yet imperfectly understood primary 

 causes of its appearance and development into a devastating 

 epidemic. I would especially draw attention, in this con- 

 nection, to the circumstance that some 17 or 18 years ago an 

 epidemic, apparently and most probably identical with the 

 fungus disease of the British salmon rivers, broke out among 

 the fish of this colony, popularly known as the fresh water 

 herring or cucumber mullet, Prototrodes marena, but which 

 may be more correctly described as a close ally of the 

 European grayling, Thymallus. This fact is recorded' in Mr. R. 

 M. Johnston's excellent catalogue of the fishes of Tasmania, 

 and has been attested to me by many residents. The fish at 

 this particular period are stated to have been seen floating 

 down the rivers in thousands, covered more or less extensively 

 with a cottony fungoid growth. So virulent and exhaustive 

 was this epidemic that many, more especially of the southern 

 rivers, were more or less completely denuded of their stock 



