CEOSSING OF BEEEDS OF FISH. 107 



never increase their weight in the fresh water after 

 their first trip to the sea, but rather fall off and 

 deteriorate. Why is it, then, that, enjoying these 

 feeding grounds in common, some thrive so much 

 better and faster than others ? It cannot be doubted 

 that it is in the nature of some breeds to increase more 

 and faster than others, even as a Hereford or Norfolk 

 steer exceeds a Welsh or Highland stot, feed him and 

 breed him how, where, and when you will. We have 

 discovered how, by the crossing of breeds of animals, 

 we can get those which carry flesh best, and increase 

 the fastest, upon a small amount of food. How easy 

 it would be, therefore, having discovered the same 

 thing with regard to fish, to transplant and cross the 

 breeds of salmon and other fish, until we found that 

 which is most valuable and suitable to our various 

 rivers. Here is another branch, then, of the science, 

 scarcely inferior in importance to the last, but of 

 which we know literally nothing. Is it not a sur- 

 prising thing, that a people whose interests are so 

 vast in the elucidation of such questions, should be 

 content to remain in ignorance of them, and should 

 make scarcely an effort to obtain enlightenment on 

 them? It would be very difficult to compute how 

 many millions a-year are lost to this country by an 

 ignorance of pisciculture. Indeed, it may with some 



