158 THE NEW ART OF BREEDING TISH. 



must be on the slightly inclined plane principle. 

 The gravel with which the trench is covered in must 

 not be pressed down, except very slightly, in order 

 not to prevent the free percolation of the water, 

 which must have full ingress and egress to and from 

 the spot where the seed lies deposited. The action 

 and contact of moving water are essentially neces- 

 sary to perfect this strange incubating process. 

 Without them ova will be non-productive, for, placed 

 in gravel at the bottom of still, or sluggishly run- 

 ning water, they wiU putrify, or, to use a generally 

 known expression, they will be ' addled.' " 



It will be seen that Mr. Young's method re- 

 quires no complicated machinery, no spawning uten- 

 sils or salmon-breeding boxes. He made his beds in 

 the soil of an old mill-race in the river Shin, and 

 took his spawn from that river. Of course the tem- 

 perature of the waters of the spawning-beds and of 

 the river was the same. His artificially bred salmon 

 fiy assumed the silvery, migratory, smolt coat at 

 the end of twelve months. This proves only that 

 the Shin salmon fry become smolts at a year old, 

 but it does not prove that to be the case in all 

 rivers. I think it is so in the great majority of sal- 

 mon rivers. I should very much like to see impreg- 

 nated salmon ova from the Shin placed in the river 

 Nith, and vice versa. If done, it would go far to- 

 wards enabling us to come to a conclusion as to the 

 age of smolts. 



Ephemeba. 

 Jan. 27. 



