ROACH AND DACE. 67 



healthy that we cannot wonder at the common saying, 

 "As sound as a roach." Its bright red fins assume 

 their most gorgeous tints about breeding time. A 

 nearly allied species, common in Norfolk, is the rudd, 

 so called on account of its still brighter tints of red. 

 When young this species may be domesticated, and 

 kept healthily alive for some time, especially if the 

 surface of the water be covered with aquatic vege- 

 tation, for it is very fond of hiding under the cool 

 shelter of such a layer, and darting out thence sud- 

 denly and vigorously on its prey. 



In the larger tanks the perch may be kept with 

 comparative ease, although it is a fish very capri- 

 cious as to diet. It is always best to begin with 

 small specimens, or those that are about a quarter 

 grown. A perch of two or three ounces weight is 

 quite big enough for ordinary size tanks, especially if 

 other animals are kept with it. In the larger ones 



Fig. 26. 



The Pike (Esox Indus). 



small pike (Esox Indus) may be preserved, but Dr. 

 Lankester calculated that a pike which weighs a 

 pound will require a tank containing 32 gallons of 



F 2 



