370 FISHES 



restricted to a single row along the lateral line, or to the back. 

 Another variety, called the leather-carp, has no scales at all but 

 owes its name to the much-thickened skin. Abnormalities of the 

 fins also occur as in the gold-fish. 



Gold-coloured varieties have arisen under domestication in 

 two other species of Cyprinidae besides the gold-fish. One of 

 these is the ide, a species of the same genus as our dace and roach ; 

 its scientific name is Leuciscus idus, and it is found in central 

 and northern Europe. The golden variety known as the golden 

 ide or orfe is bred in Germany. Two hundred specimens 

 were introduced into the Duke of Bedford's ponds at Woburn 

 Abbey in 1874 and lived there for many years. Similarly 

 golden, red, and black-spotted varieties of the tench, Tinea 

 vulgaris, have been produced under domestication in Germany, 

 and occasionally introduced into England ; these colour varia- 

 tions are said by Siebold (1863) to occur in the wild state in 

 Upper Silesia. 



