Eden every year. As many as 600 diseased salmon were 

 taken out of the Lime, which is but a small river, last year. 



The course of the epidemic has been very remarkable. 

 It began to attract attention in the River Eden in 1877 ; 

 shortly afterwards it appeared in the Tweed, and it has 

 remained ever since in great but variable intensity in those 

 and adjacent rivers. On the east coast, a few cases have 

 appeared in the Coquet, but none have been noticed in 

 the Wear. Among fresh-run salmon it is almost un- 

 known on the Tyne, though it commonly appears on 

 kelts and on dace. But it has never taken an epidemic 

 character in this river nor in the Tees. In the Yorkshire 

 Esk fifty diseased fish were taken out in 1882, but there 

 has been no serious epidemic. Two or three diseased 

 salmon were taken out of the Ure last season, but south- 

 ward of this I have no information of any disease in the 

 rivers of the east coast. 



It may be said, then, that there has been practically no 

 epidemic outbreak in the eastern rivers south of the Tweed. 

 On the west coast of England the state of affairs is totally 

 different. Since 1879, the disease in its epidemic form has 

 made its appearance more and more to the south, until last 

 season it broke out in the Usk and in the Wye. 



These facts are very remarkable and very important. 

 For if, as I believe to be the case, the morbid affection 

 the skin is wholly extirpated when the salmon descend to 

 the sea, it is not possible that the disease should be pro- 

 pagated from one river to another by the immigration of 

 fish from an infected into a healthy river. It is quite 

 possible that the fungus which, as we shall see, is the cause 

 of the disease, might be transferred from an infected to a 

 healthy river by birds, but the evidence in the Tyne and 

 in the Usk is conclusive that the disease has long existed 



