NATURALIZATION OF SALT-WATER FISHES. Ill 



it possible that they may ever be made thriving 

 denizens of fresh water, or otherwise be subjected 

 to the immediate control of man ? It has been af- 

 firmed that they may, and hence we must not omit 

 the subject. It has been contended that this change 

 of habit has been effected in the Common Cod, the 

 Plaice, Flounder, Mullet, and other fishes. The 

 evidence we can adduce on this point must neces- 

 sarily be much curtailed. That the Cod can reside 

 permanently in fresh water. Dr. M'CuUoch affirms 

 lias been proved in Shetland ; the inlet of Stromncss- 

 voe in the Mainland, communicating indeed with 

 Ihe fresh-water lake, bat by a channel so narrow 

 that the tide is never able to pass the strait of com- 

 munication, but merely dams the fresh water tiU 

 the ebb again commences. That the water is per- 

 fectly fresh, he says, is certain ; also that Cod are 

 frequently taken in it, and that the inhabitants en- 

 tertain no doubt it is a permanent residenter. The 

 Plaice, Pleuronectes plaiessa^ according to the same 

 authority, has been carried from the North Sea to 

 the ponds of East Friesland ; and with regard to 

 the Mullet, both in Guernsey and Sicily, this strik- 

 ing change seems to h;ive been effected. At one 

 ^ime a number of Grey Mullet, about a finger-length, 

 wefe placed in a pond of three acres of area, in the 

 Channel island, the water being perfectly fresh : 

 they increased in size, and nurtierous fishes of four 

 pounds vyeight have been taken from the pond, so 

 that this experiment iA complete and satisfactory. 

 In Sicily the Mullet is cultivated in the lake Biviere i 



