[45] FISH CULTURE IN CENTRAL EUROPE. 583 



The hatching-troughs are of wood carbonized on the inside ; their 

 number is 20, and they are arranged in groups of 4 each. The frames 

 used are those of Coste, and others having a network of metal wire. 

 Some California boxes of various systems are also used. 



The fish raised in this establishment are river trout, lake trout, 

 Thymallus, Salvelinus, and cross-breeds of Salvelinus ( $ ) and trout ( 9 ); 

 also some American species, as Salmo sebago and Salvelinus fontinalis. 



Besides the above-mentioned hatching-house, there is another smaller 

 one, fed exclusively by spring water, where, besides ordinary troughs^ 

 circular porcelain apparatus (according to the La Vallette system) are 

 used. 



There are also 20 ponds of different size for young Salmo sebago and 

 American Salvelinus, from which, though only two years old and not 

 more than 15 centimeters [0 inches] long, Mr. Zenk has already obtained 

 eggs. In these ponds there are also carp, bass, tench, and golden ort 

 (Idus melanotus var. aureus). 



In the large hatching-room there can be kept and developed about 

 G,000,()00 trout eggs. 



5. Cosmandorf. — Near the village of Cosmaudorf, between Dresden 

 and Tharand, in Saxony, a short distance from the confluence of the 

 "red" Weisseritz and the "wild" Weisseritz, there is a small fish-cult- 

 ural establishment belonging to Mr. Mittag, one of the proprietors of 

 the fisheries in the Weisseritz and the Wesenitz, who, among other 

 economical enterprises has undertaken to restock these waters by means 

 of artificial fish-culture. He does not receive any direct subsidy from 

 the Government, but it furnishes him gratuitously the einbryonated 

 salmon eggs, which are to be placed in the Weisseritz ; and also pays 

 him 31 cents for every thousand young salmon which have been hatched 

 iu his establishment. Mr. Mittag is, however, obliged to furnish the 

 necessary material for Prof. Nitsche's fish-cultural course at the Tha- 

 rand Academy of Forestry. The establishment has been in existence 

 about six years. Some time before this another much larger establish- 

 ment was founded, but proved an entire failure. 



The water is supplied by a mill canal which comes from the " red " 

 Weisseritz, and also furnishes the water-power for a manufactory of 

 wood material (pasteboard). The water is not filtered, although this 

 would be beneficial on account of the sediment from the manufacture 

 referred to above. The temperature, during the hatching season, 

 varies from 1° to G° C. [34° to 43° P.]. 



The hatching-house is small ; it has double wooden walls with a layer 

 of hay between them. The water runs along one of the walls in a 

 wooden canal. It should be noted that the faucets of the pipes through 

 which the water flows into the hatching apparatus are not, as is gen- 

 erally the case, on the sides of the pipes, but at the very end of the 

 pipe, in order to make it more difficult for the sediment to gather. The 

 hatching apparatus which I saw consisted of twelve California boxes, 



