58 AMPHIBIANS AND FISHES, 



that the capacity of the tank is sufficient to allow of 

 necessary vegetable growth to provide them with air. 



Of all the favourite species the goldfish has long 

 been most domesticated, so that now, like the canary 

 among birds, it seems to be better adapted to confine- 

 ment than even to a free roving life. It will answer 

 admirably in a tank supplied with Anacharis, the 

 tender shoots of which it eats with great relish. This 

 and an occasional blood-worm will serve for all the 

 food it requires. Where fish are kept the utmost care 

 should always be taken that no bread or biscuits are 

 ever given to them, as these not only injure the fish, 

 but contaminate the water by their speedy decompo- 

 sition, unless the water is exceedingly well oxygen- 

 ated. Care has also to be bestowed upon the Ana- 

 charis in such tanks as may contain it, for, as its only 

 method of reproduction in this country is by budding, 

 the latter process is apt to take place so vigorously as 

 speedily to fill the water with a densely-crowded mass. 

 It may always be made to grow by planting a sprig 

 in a flower-pot containing soil, and placing this among 

 the rockwork, so as to be hidden away. 



Undoubtedly those of our native fishes which are 

 easiest to obtain and domesticate are the stickle- 

 backs and the minnows. We have several species of 

 the former, some of which will live equally well in 

 fresh and salt water aquaria ; and as some of them 

 indulge in the unfishlike recreation of nest-building, 

 they become really very interesting objects when the 



