CROSS-BREEDING OF FISH. 8l 



proportionate to the cross. We then crossed this 

 fish with the brook trout, which gave us a fish one- 

 eighth salmon trout and seven-eighths brook trout, 

 and these fish can scarcely be told from the straight 

 brook trout, even by an expert. 



I have also made other attempts at crossing dif- 

 ferent breeds of fish with more or less success, but 

 as yet I cannot say that any particular practical 

 benefit has been derived from such attempts. They 

 are valuable in so far as demonstrating what can 

 be done in this direction. In fish culture as well as 

 nearly everything else, all discoveries of value have 

 been the result of actual experiment, and it is 

 through this means that we ascertain the truth or 

 falsity of our theories. 



