THE PROPAGATION OF THE GOLDFISH 



is also less severe on circular than rectangular basins and a basin of this 

 kind is more likely to be lifted off the bottom than to break the sides by 

 the pressure, and is easily repaired by filling in the bottom crack with liquid 

 cement. All tanks should be seasoned before the fishes are introduced 

 by a thorough soaking and frequent changes of water, to remove all traces 

 of soluble lime or acid substances. 



When not in use, it is a mooted question whether they should be 

 kept dry in winter or partially filled with water to equalize the pressure 

 of the frozen ground. Good results have been obtained by filling with 

 water and floating logs in them to relieve the sides of ice pressure, while 

 freezing will destroy fungus and disease spores. 



Greenhouse Culture. Experience has taught breeders of the gold- 

 fish that the principal purpose of the greenhouse is the wintering of the 

 breeding fishes, keeping over young fishes for better prices when the 

 general supply is exhausted, and for spawning, hatching and rearing of the 

 fry during the early weeks of the spawning season, when the possibility 

 of late frosts may endanger them out-of-doors, though early spawning is 

 not to be generally recommended. 



Another purpose of the greenhouse is the facilities it affords in con- 

 tinuous growth of the young during the winter months, as aquaria and 

 small household tanks tend to arrest development; also for the preserva- 

 tion of the necessary aquatic plants over winter. Young fishes, however, 

 thrive best in the open air. 



Compartment tanks and cement basins, should be arranged to place 

 as many as possible in the available space, and to permit of ready access 

 and inspection. When the weather has become settled, the rearing should 

 be done out-of-doors. Great care must be exercised in seasoning these 

 receptacles. 



The illustration, Fig. 58, is a greenhouse for goldfish propagation 

 designed by the author, which may be erected in a back yard or garden. 

 AH the sash of the sides and roof are hinged, to permit of raising or re- 

 moval in warm weather for the free circulation of air, a prime essential to 

 success. The spawning and hatching tanks are arranged at the sides, to 

 permit of a central aisle, and the overflow connections led to the drainage by 

 pipes with union joints. The water supply is by a hose. The rearing 

 tanks are shown adjoining the greenhouse but may be located within con- 

 venient distance and should be provided with portable glass sash as covers 

 on cold nights and mornings and with wire screens to keep out enemies. 

 If the screens are of galvanized iron, they should be thoroughly cleansed 

 and seasoned, to remove the acid. 



104 



