BREAM. 109 



Mussel, and the fry take their departure in about a month's time. 

 The young fishes cannot be regarded as parasites in the gill of the 

 mollusc, since they subsist solely on the yolk that is present in 

 the egg. All that they enjoy is apparently the safety of the 

 secluded position and a current of fresh water which the Mussel 

 keeps circulating through its gills for its own respiratory pro- 

 cesses. The young of the Pond-Mussel, when discharged by their 

 parent as free-swimming little creatures, have a way of hooking 

 themselves on to the skin of freshwater fishes, and living embedded 

 in the skin for some time before they escape and settle down in 

 the mud to complete their growth. The breeding-seasons of the 

 Mussel and the Bitterling coincide, and the Mussel takes its 

 revenge, so to speak, on the Bitterling by discharging its own 

 young upon the mother-fish, so that the skin of the latter becomes 

 a nursing-ground for the young Mussels. 



The Bream, Abramis brama, 349, may be distinguished from Bream, 

 the other fresh-water fish of Britain by the great depth of its 

 laterally compressed body and the considerable length of the base 

 of the anal fin. The dorsal fin has a short base and stands high, 

 and the lower lobe of the tail-fin is longer than the upper. The 

 scales are rather large and number 51 to 57 along the lateral line. 

 The Bream is as much at home in rivers as in lakes, and is found 

 in most parts of temperate Europe north of the Alps. The fishes 

 swim in large shoals and feed partly on water-weeds and partly on 

 aquatic insects and worms. The average weight of a Bream in 

 England is between 2 and 4 lbs., but a specimen has been caught 

 in the Serpentine, in Hyde Park, weighing more than 7 lbs., and 

 larger sizes are on record. 



The White Bream or Bream-flat, Abramis blicca, 351, is a Bream- 

 smaller fish than the Common Bream, and in England not so flat - 

 abundant. It is one of the commonest, fishes of Central Europe. 

 The colour is whiter and more silvery than that of the Bream, and 

 less brown and brassy, the lobes of the tail-fin are not so unequal, 

 and the pharyngeal teeth are arranged in two rows on each side 

 instead of in a single row. The fish rarely exceeds 1 lb. in weight, 

 or a foot in length. 



The Carp family is remarkable for the fact that some of the Hybrids, 

 different forms cross-breed in a state of nature, i. e. not in 



