CULTURE OF THE CARP. 557 



fed from the drainage of the soil rather than from streams, be- 

 cause the former is richer iu nutriment. By leading in water 

 from the adjoining water-sheds, from cultivated land, and villages, 

 the ponds are much improved. When creeks or brooks flow 

 through the pond, a brush-weir, formed of layers of uutrimmed 

 brush-wood, in such a way that the fish cannot pass over it, must 

 be placed so as to prevent the ascent of the fish in the stream. The 

 water-level should, as a rule, be maintained as constant as possible ; 

 and, in summer, a sudden, large influx of water should be prevented, 

 because the fish swim very eagerly toward the current of fresh water, 

 and are thus drawn from their feeding-ground and are liable to be 

 stolen. In a dry season, if the addition of water is unavoidable, it 

 should only be allowed to flow in during the day and be stopped at 

 night. It is important to be able to turn fresh water into the fish-pit, 

 when the pond is fished out, in order to revive the fish when they 

 become languid. If the water falls in dry weather, the borders become 

 dry, fermentation and putrefaction of the marsh-vegetation occur, and 

 the carp leave their feeding-ground for deep water. The spawn laid on 

 the grass iu the breeding- ponds also become dry and dead. On the 

 other hand, it is advantageous to allow ponds, prepared the summer 

 before, to dam up gradually, so that the higher portions may be pas- 

 tured, and breeding-places be afforded to insects. As these portions 

 are in succession rendered accessible to the carp, by the gradual rise of 

 the water, they are eagerly sought out by them. This plan has greatly 

 increased the productiveness of the ponds in Peiz, as well as in Wittin- 

 gau. Since carp find their food, for the most part, on the flat margins 

 of the pond, it is in general better to lay out several small, shallow 

 ponds than one large, deep one. Floating masses of vegetable matter 

 and marshy growth reduce the productiveness. Eepeated mowing in 

 summer, under water, and burning the roots when draiued and dried by 

 exposure, are employed to prevent the latter ; the former are intersected 

 in different directions by ditches, when the knots of vegetable matter 

 will float to the shore, and may be drawn out ; or the marsh may be 

 covered, when drained, if necessary when frozen, to the depth of several 

 inches with sand, which will prevent their floating when the pond is 

 filled. In the winter it is beneficial to allow the water to flow in and 

 out of the pond. If it becomes covered with ice, this is removed, at 

 such a distance from the wintering-place of the fish that they may not 

 be reached with a spear. In Wittingau, such openings in the ice, in 

 the larger ponds, are cut from 40 to 65 feet long and 3 to 4 feet wide, 

 and the ice is removed twice a day by means of hooks. If a decided 

 thaw occurs, when the ice is covered with a considerable depth of snow, 

 and the latter becomes saturated with water, and freezing weather fol- 

 lows, the preservation of the fish through the winter becomes doubtful. 

 The water generally changes color to yellowish, milky-white, or brown- 

 ish ; and sluggish insects appear at the openings in the ice and die, and 



