AND OF STILL WATERS. 53 



and, as Couch remarks, " there lies concealed, 

 perhaps for a longer time than is pleasing to 

 himself, although from the power he possesses 

 of extracting the minutest portions of air from 

 almost exhausted water, he continues to live 

 where other fish must have perished." This 

 peculiarity has afforded scope for experiments, 

 which have proved that the tench is able to 

 breathe when the quantity of oxygen is reduced 

 to the five-thousandth part of the bulk of water ; 

 ordinary river- water generally containing one 

 per cent, of oxygen. Dr. Roget observes " that 

 this fact shows the admirable perfection of the 

 organs of this fish, which can extract so minute 

 a quantity of air from water, to which that air 

 adheres with great tenacity." Obviously the 

 power to live under circumstances which would 

 kill many other fish, greatly increases the value 

 of the tench as a marketable commodity. Like 

 his cousin the carp, he can be conveyed long 

 distances to market, packed in straw or wet 

 moss, and if not sold, can be brought back to 

 the pond or stew whence he was taken, to 

 await another occasion for sale. 



