76 FISHES AND FISHING. 



written, relative to the mixed breeding of some of 

 our most valuable fish. It is a subject deserving 

 serious consideration and experiment ; for instance, 

 Bay the ova of a trout vivified by the milt of a salmon, 

 we suppose, upon the above hypothesis, should be 

 outwardly formed like a salmon ; but what its migra- 

 tory propensities, or necessity for periodically visiting 

 the salt water might be, it is impossible to form an 

 opinion, without actual experiment ; and so with the 

 ova of a salmon vivified by the milt of a trout, we 

 should expect the outward shape to resemble the 

 trout species, but what disposition would be produced 

 for constantly abiding in fresh water, we have to 

 learn, or whether either of these fish would be trou- 

 bled with those parasitical plagues as the salmon are, 

 would be seen, if the theory proved to be a fact. It 

 certainly would be a most desirable consummation to 

 arrive at, if rivers could be stocked with fish of the 

 salmon species, which had not the necessity to migrate 

 to the sea. If the Thames particularly could be 

 stocked with a fish of this description, without its 

 migratory necessities, as thereby the filthy water 

 of the river, from Battersea downwards, and the 

 immense traffic of steam boats, would be of no 

 importance, as to the fishery of our noble river. I 

 sent a copy of this to Thomas Ashworth, Esq., and 

 in his little work, pp. 18 and 19, are some observations 

 on the subject. 



