C. WAGNER ESTABLISHMENT FOE EAISING GOLDFISH. 681 



macliine-liouse, these pipes are but rarely used. In case of necessity, 

 i. e. when the stagnating spawning-ponds require it, a movable wooden 

 pipe is used, through which the water of the stream is pumped into 

 every pond whose water needs stirring up. On its way the water be- 

 comes completely satiirated with oxygen, and its effect on mature fish is 

 so quick that they often commence to spa^vn within an hour from the 

 introduction of the fresh water. 



As the bottom of the dikes is composed of very porous soil, the water 

 goes from one pond to the other, and the depth of water is about the 

 same in all the ponds, any superfluous water being led out through the 

 channels c into the main outlet-canal h. 



Although at times the depth of water in the ponds is only ^ foot, the 

 average depth is about 2 feet, increasing to 4 feet near the outlets. The 

 extent of surface is of greater importance than the depth of water, the 

 average surface of each i)ond being about 228 square yards. 



The bottom of the i)onds is purposely left uneven, and is here and 

 there overgrown with aquatic jjlants, on which the goldfish love to de- 

 posit their eggs. 



The dikes between the ponds are generally 6 feet high, while the outer 

 dikes are 8 feet high, 10 feet broad at the base, and 3-4 feet at the top. 

 As the incline is therefore very gradual, and as the grass tends to keep 

 the soil together, the bottom of the dike, though i)orous, is nevertheless 

 firm. 



The chief results of Mr. Wagner's cultivation of goldfish during sev- 

 eral successive seasons are as follows : Many fish commence to color at 

 the end of the first year ; they are large enough to be sold for aquaria in 

 the autumn of the second year, and they may be made to spawn two or 

 three times a year, as a large number reach their maturity when only 

 twelve months old. 



By good feeding and frequent redistribution of the female fish (not 

 allowing the same males and females to be together any very consider- 

 able length of time), and by an occasional airing of the water as de- 

 scribed above, it has become possible to fix the time of spawning to the 

 very day, and to raise a large number of young fish from comparatively 

 few spawners. Under favorable circumstances the first young fish are 

 raised in March or April, and by adopting the above-mentioned meas- 

 ures a second set of young fish may be raised in July or even earlier, 

 and a third in August or the beginning of September. 



It is but natural that fish cannot spawn so often during one season 

 and at so early an age without many of them becoming prematurely 

 barren. These barren fish, which can easily be recognized by a sunken 

 appearance of the parts back of the ventral fin, must of course be sepa- 

 rated from the others. They can only be sold as ornamental fish. Even 

 if the spawning process is not hurried too much, it is an exception if a 

 fish is used for spawning more than three years. 



Mr. Wagner's average spawning stock amounts to about 3,000 fish, 



