OF GREAT BRITAIN. 103 



derable journey in the broiling heat of a July or 

 August day with no more moisture than could be 

 obtained from a damp cloth, and yet they have 

 been alive, and even lively, at the end of it. The 

 idiosyncracy is so well known and acted upon that 

 in Holland it is no uncommon practice to fatten 

 Carp for the table by hanging them in a cellar in a 

 net full of moss kept damp, and feeding them, like 

 babies, on bread and milk poked into their mouths 

 with a spoon. 



The capacity of enduring this sort of amphibious 

 existence is no doubt due to the construction of 

 the fish's breathing apparatus, which is peculiar. 

 The supports of the gill-leaves are bony ; whilst in 

 the Perch they are formed partly of bone and 

 partly of cartilage, and in the Bream, Barbel, and 

 Pike wholly oi cartilage. The consequence is that 

 instead of becoming stuck together when deprived 

 of the moisture of the water, these gill-leaves, 

 which represent the lungs of the fish, can be sepa- 

 rated by the action of the muscles so as to absorb 

 the oxygen from the air — in other words to breathe. 

 In the Carp also the gill-openings, which in the 

 Salmon and Trout are equal in extent to the length 

 of the gill-arches, are partially closed by a mem- 

 brane, thus enabling them to retain moisture. 



I have seen it stated, though I cannot say that I 

 have met with an instance within my own know- 

 ledge — that upon the drying up or exhaustion of a 

 pond the Car[) that were in it will bury themselves 



