125] POND CULTURE. -jjj^ 



near the air-holes, there are seen in them small, and soon also large spi 

 ders and beetles in a languid condition or dead; and one or two days 

 later, fish begin to make their appearance in the air-holes more or less 

 languid and gasping for breath. If the water of a pond becomes 

 spoiled, the first to sufler and die are the crawfish, next come the 

 frogs, then the fish of prey, and last of all the carp. At the first indi- 

 cation of such a condition of affairs crows begin to hover around the 

 pond and about the air-holes, and thus become in truth birds of ill 

 omen to the pond cultivator."* 



The only help in such cases, which cannot be brought too soon, is the 

 immediate introduction into the pond of fresh water and fresh air! The 

 latter object is reached by quickly making as many air-holes as possible, 

 and fresh water is introduced by freeing the ditches from ice and by 

 increasing the depth of water as rapidly as possible. The ditches 

 through which the water flows out should of course also be freed from 

 ice, so that the water in the pond is kept in constant motion by the fresh 

 water flowing through it. This process should be continued until all 

 the vitiated water has been removed. If this cannot be done quickly 

 enough, or if it has not the desired effect, so that fish gasping for air 

 crowd the air-holes, and if there is no immediate prospect of thaw or 

 rain, it becomes an imperative necessity to take all the fish out of the 

 pond and transfer them to another one. The appearance of a few fish in 

 : the air-holes should not cause the pond cultivator immediately to empty 

 , out the pond, for these may be only fish which have fallen sick from some 

 ' other cause, and have therefore sought the fresh air. Such fish should be 

 I carefully examined with a view to ascertain the actual cause of their 

 having left the depths of the pond. Carp which are suffering in cou- 

 I sequence of a vitiation of the water have, according to Horak, always an 

 ; unusually large gall bladder, a bluish mouth, and a pale color generally. 

 , Carp which shoM- these signs should not be used for stocking ponds. 

 i The fish which have been removed from a pond whose water has 

 I become vitiated should not be placed in the same winter ponds with 

 i other fish ; for they are languid and sick, and are apt to give their dis- 

 ease to the other fish. If some of the fish should die after they have 

 . been removed to another pond they will corrupt its water, and the first 

 loss is followed by a second one. * Sick fish should, therefore, be trans- 

 ' ferred to ponds which contain no other fish, and the importance of hav- 

 I ing a few supernumerary winter ponds will be recognized. In order to 

 prevent such occurrences, or at any rate to bring speedy relief, winter 

 I ponds should at all times, but especially during severe winter weather, 

 ; be kept under the most careful supervision. The water, however, may 

 I become vitiated, and the fish die, even if it is not covered with ice, 

 I unless fresh water is from time to time introduced into the ponds, 

 and the same may occur if the winter ponds are too much crowded. 

 Pond cultivators should, therefore, see to it that their winter ponds are 



* Horak, Teichicirthscha/t, 1669. 



