54 



March K)t/z, ii 



Allan P. Swan, Esq., read a Paper on 



THE FUNGUS OF SALMON DISEASE : ITS 

 LIFE AND FUNCTION. 



It is only about twelve years since the first outbreak of what has 

 since been known as the " Salmon Disease," or " Salmon fungus," 

 occurred in the rivers Nith and Esk, that flow into the Solway 

 Firth. The disease rapidly spread to several adjoining rivers, 

 and in the spring of 1879 it broke out with great virulence in 

 the Tweed, and in little more than another year had extended 

 to the rivers Annan, Eden, Cree, and Dee, all running into 

 the Solway Firth ; to the Derwent in Cumberland, and the 

 Lune in Lancashire. It had also spread northwards to the 

 rivers Doon and Ayr in Ayrshire, and since then has extended 

 to many other Scotch rivers, among the first of which were the 

 Tweed and North Esk. 



The disease did such immense injury that a Commission was 

 appointed in 1880 to investigate it, and a report, which was 

 published in the Annual Circular of the Fishery Inspectors for 

 England and Wales for 1881, contains a very full description 

 of the fungus, and the manner in which it grows on fishes and 

 causes their death, with a most interesting account of its known 

 life history, and many of the influences that can favour its pro- 

 pagation, besides evidence from the localities where the disease 

 was prevalent in its virulent form. 



Other reports of the inspectors published since 188 1 con- 

 tain additional information, and much new evidence has 

 been carefully collected by persons living near the affected 

 rivers, whose practical observations have been recorded on all 



