SALMO SALAK. 277 



Mr. St. John tells iis that Mr. Young", who manag-es the fisheries of 

 the Duke of Sutherland, thinks that Sea Trout and Salmon interbreed, and 

 records the following evidence :— " A pair of Salmon, male and female, being 

 seen forming their spawning-bed together, the male Salmon was killed with a 

 spear and taken out of the water. The female immediately dropped down the 

 stream to the next pool, and, after a certain interval, returned with another 

 male. He having shared the same fate as his predecessor, the female again 

 went down to the pool, and brought up another male. The same process was 

 gone on with of spearing the male, till the widowed fish, finding no more of 

 her own kind remaining in the pool, returned at last accompanied by a large 

 River Trout, who assisted her in forming the spawning bed, etc., with the 

 same assiduity that he would have used had she been a Trout instead of a 

 Salmon. ^^ 



Sir J. Gibson Maitland has endeavoured to produce hybrids between 

 Salmon and Loch Leven Trout, his experiments being fully recorded by 

 Mr. Day, in a series of communications to the Zoological Society ; but, 

 although multitudes of fish are reared successfully, hitherto the hybrids have 

 proved sterile. At an age of eight months the young Parr have from ten to 

 thirteen finger marks along the sides. At twenty months old some have 

 twelve marks on both sides, and occasionally ten on one side, and eleven on 

 the other. 



Professor Malmgren believes that certain Salmon in a lake in Finland 

 are descendants of the common Salmon, which have ceased to have communi- 

 cation with the sea owing to elevation of the land, and the result has been 

 a dwarfed race, with smaller eggs than those of Salmo salar. 



For some years Salmon have been liable to an epidemic disease which 

 has caused a large number of deaths in the rivers of Scotland, the north 

 of England, and North Wales. According to Huxley, the first symptom 

 of the malady is the appearance of greyish patches upon the skin of the top 

 and sides of the head, the adipose fin, or the bases of the other fins ; in fact, 

 upon those parts of the body which are not defended with scales. When first 

 observed the patch may be a circular spot no bigger than a sixpence, but it 

 soon increases in size, becomes confluent with other patches which may have 

 appeared near it, and extends over the healthy skin. The central part, which 

 had at first a raised softer centre, acquires the consistency of wet paper, and 

 the true skin beneath it ulcerates, and an open bleeding sore is formed, which 

 may extend down to the bone. The disease gradually spreads over the whole 

 of the back and sides, and extends into the mouth. This is a contagious and 

 infectious disorder, comparable to ring-worm, or the })otato disease, or muscar- 

 dine among silk-worms. It is the work of a minute fungus named Sajorolegnia, 



