28 THE FRESH-WATER FISHES OF EUROPE. 



The fish is not migratory, though it is capable of living out of water For 

 some hours, and is often carried long distances in wet grass. In Catholic 

 countries individuals remaining unsold in the market are again returned to 

 the ponds, as is the case in some parts of the middle of England, as at 

 Peterborough. 



Many deformities of the Perch have been described, the back becoming 

 greatly elevated, and the tail distorted. With old age Perch become dark in 

 colour, and blind. The density of the cornea has been attributed to in- 

 flammation, produced by parasites in the aqueous humour of the eye. Re- 

 markable epidemics have destroyed the Perch in some of the Swiss lakes 

 in great numbers. One of these has been attributed by Dr. Forel and Dr. 

 Du Plessis to the presence of bacteria in the blood, and is regarded as a 

 form of typhus fever. The Perch suffers from many small parasites; the 

 mouth is infested by a crustacean (Achtfieres percce) ; the body is attacked by 

 leeches (Ichthydbdclla percci) ; the skin, muscles, cephalic cavities, branchiae, 

 liver, digestive canal, are all subject to the attacks of entozoa and other para- 

 sites. The Perch is introduced into Trout ponds in North Germany as food 

 for the Trout. 



In Britain the Perch is absent from the extreme north; and Yarrell 

 speaks of it as only sparingly met with in the lochs north of the Forth. 

 In Scandinavia it occurs as far north as Lapland, where it reaches a large 

 size. It is spread nearly all over Europe, and found generally in the Alps to 

 the height of upwards of 4,000 feet. 



It occurs in the Sea of Azov, in the brackish water of the Caspian, and 

 over a large part of Northern Asia. 



The name Perch was first used by Aristotle, and is, therefore, of Greek 

 origin. It is a term applied to the dusky colour of ripening grapes, and is 

 supposed to indicate the spotted or banded marking so characteristic of this 

 fish. With the Romans it was Perca, with the Germans it is BarscJi , in 

 which the " P " has become changed into a B." From this the Dutch Baars 

 is readily derived, a name which appears to have been adopted into the east 

 of England with slight variation of spelling. All these Teutonic names signify 

 barred or banded fish. In France it is la Perche, in Italy Persico. In Bavaria 

 it is Burstel, in Lake Constance it is the Egli, in Sweden the popular name 

 is Aborren. Dr. Day mentions that the Saxons represented one of their gods 

 as standing with naked feet upon the back of a Perch, as an emblem of 

 patience in adversity. 



