[49] FISH CULTURE IN CENTRAL EUROPE. 587 



each of these hatching apparatus there is attached a small box, intended 

 to gather the young fry after they have slipped out of the egg. When 

 this has taken place, the young Coregoni fall into the basins below, which 

 have about 3 centimeters [If inches] of water, while the young salmon 

 and trout are left in the hatching-boxes. The hatching apparatus have 

 covers, because otherwise one rat could in one night destroy the entire 

 contents. The room can be heated artificially. Besides eggs of various 

 German salmonoids, I saw in process of hatching eggs of American 

 Coregoni and Salvelinns. 



Mr. von dem Borne also has 22 ponds, the largest covering an area 

 of 11£ hectares [about 28^ acres]. In these there live and are raised 

 fish of many different kinds — salmonoids, cyprinoids, &c. In the ma- 

 jority of the ponds, however, there are carp, the ponds being arranged 

 according to the Dubitsch system, already described by me m another 

 report. Among the foreign kinds the black bass {Euro nigricans) from 

 Florida deserves special mention, as Mr. von dem Borne has succeeded 

 in propagating this fish in his ponds. This kind, like the bass and some 

 other fish, deposits its eggs among stones; and it is therefore necessary 

 to prepare a bed of small stones in the place where it is intended they 

 shall spawn. 



10. Michaelstein. — In 1880, by an agreement between the Governments 

 of Prussia, Brunswick, and Anhalt,for the purpose of stocking the pub- 

 lic waters of the Harz Mountains, a fish-cultural establishment was 

 founded in Michaelstein, near Blanko*iburg, with Mr. Dreckmaim, su- 

 perintendent of forests, as director. After his death Mr. Wegener be- 

 came its director. As far back as the Middle Ages there were in this 

 neighborhood carp ponds, constructed by the monks. 



The water comes from one of the ponds close to the establishment 

 and passes through a small grating; thence it passes into a filter com- 

 posed of six boxes, the first containing pieces of sponge, the second 

 sand, the third again sponges, and" so on, alternating. In winter the 

 temperature of the water falls to the freezing-point. After the water 

 has reached the hatching-room it is, by means of faucets, to which small 

 flannel bags are sometimes attached with the view to better filtration, 

 distributed through the apparatus, which are California boxes modified 

 according to the Schuster system. These boxes are arranged on 

 wooden staircases, each of the 14 steps containing two boxes ; there- 

 fore in all 252 boxes. Each box may contain about 10,000 trout eggs. 

 There are also 4 large cemented tanks for grown trout, and some wooden 

 troughs, which are only used in case of absolute necessity. Besides 

 river trout, Salvelinus and American trout are raised in this establish- 

 ment. Some of these, two years old and weighing about 3 pounds, 

 have already propagated the species under artificial cultivation. 



There are a great many ponds, some of which might possibly be used 

 for trout, and others for salmonoids, while in others carp alone can be 

 raised, because the bottom is too muddy for others. In these ponds are 



