SALMON. 33 



that the produce, if any, might be what is called in 

 the Tweed the Bull Trout, which exactly resembles in 

 outward appearance and general size what one would 

 conceive such a process would create. 



I learn from Mr. Shaw's last paper that he has suc- 

 ceeded in breeding the Sea Trout by artificial impreg- 

 nation with their own species; so that the produce 

 of this cross, that is, of the River Trout and Salmon, 

 cannot be the Sea Trout of the Spey and other rivers, 

 but may possibly prove what I suggested. It is at 

 least a very curious coincidence, that the Tweed, which 

 abounds in common Trout, abounds also in Bull Trout ; 

 whereas in the Annan and the Tay, where Trout are 

 very scarce, the Grey or Bull Trout is very scarce also. 

 But though crosses may be produced by mechanical im- 

 pregnation, it is a matter of grave consideration whether 

 such take place naturally. Trout, however, are always 

 seen near the spawning beds of the other Salmonidce. 



" The young of these Sea Trout," says Mr. Shaw, 

 "at the age of six months bear no very marked re- 

 semblance to the young of the real Salmon, either in 

 the parr or fry state ; and as they advance in age and 

 size the resemblance becomes still slighter. But upon 

 comparing them with the common Trout, the resem- 

 blance is very striking, the general outline of the fish 

 being much less elegant than that of the young Salmon 

 or Parr ; the external markings being also more pecu- 

 liarly those of the Trout species ; so that in the absence 

 of the parent skins, which I carefully preserved, it 

 would be a matter of difficulty to determine to which 

 kind of Trout they actually belong." 



D 



