VII 



IT is satisfactory to note (1903) a very important discovery 

 in relation to the salmon disease, whereof the 



The true . . 



salmon origin and nature have been keeping scientific 

 Disease m q u i rv a t bay for more than a quarter of a 

 century. The disease first attracted attention in the year 

 1877, when large numbers of salmon perished in the 

 rivers of the Solway. The fish affected showed at first 

 whitish patches on such parts of the skin as were not 

 protected by scales the head, the adipose fin, and the 

 bases of other fins. These patches appeared to be caused 

 by a fungoid growth; they spread, became confluent, 

 formed deep ulcers eating into the muscle, until the fish 

 became weak and stupid, drifting into the shallows, and 

 wallowing languidly till it died. The disease, which has 

 reappeared at uncertain intervals in nearly all British 

 salmon rivers since 1877, probably existed as an epizootic 

 before that date, although no previous record of its ravages 

 has been preserved. 



The late Thomas Huxley, being appointed Inspector 

 of Fisheries in 1881, had his attention drawn to it. 

 Recognising the vegetable growth upon the ulcers as 

 Saprolegnia ferax, a mould or fungus closely related to 

 that to which is attributed the potato disease, he came to 



