[31] FISH CULTURE IN CENTRAL EUROPE. 569 



The Idus mclanotus, especially its small variety, rivals and perhaps 

 excels the goldfish in brilliancy of color, which changes with its differ- 

 ent ages. 



The tench (Tinea vulgaris) is another cyprinoid which is cultivated to 

 advantage, especially its golden variety, which is kept in aquariums. 

 The manner of raising this fish differs but little from that of the carp, 

 as it is quite customary to stock ponds both with tench and carp. 



III.— Other kinds of fish. 



Pike. — At Kadolfszell, Mr. Dietrich, the manager of Mr. Schuster's es- 

 tablishment, has been successful with the artificial fecundation of pike 

 (Esox lucins). The eggs of the pike are very small, the embryo devel- 

 ops very rapidly, and the young are hatched in about twelve days. 

 They were placed in a small lake, where they did well but did not prove 

 amadvantage to the other fish. Mr. Max von dem Borne has also been 

 successful in fecundating pike eggs. As far as I know, fecundation of 

 pike eggs has not been attempted at Liibbinchen, where these voracious 

 fish are kept only in the growing ponds, to keep the carp from spawn- 

 ing. Here they are kept in company with the Lucioperca sandra aud 

 the perch (Perca vulgaris), which last-mentioned fish is considered to 

 diminish any excess of small fish, as they take away the food from 

 fish which are the proper object of fish-culture. 



Black bass. — Successful experiments in acclimatizing this American 

 fish (Euro nigricans Cuv. & Yah, Micropterus salmoides Laeep.) have been 

 made at Berneuchen. The number of individuals of the first importation 

 which survived the long journey was very small; but from the 3 which 

 survived, Mr. Max von dem Borne obtained about 1,300 young fish. I 

 have mentioned this new branch of fish-culture, because Mr. v. d. Borne 

 thinks that it is adapted to the rivers of southern Italy; and I must 

 confess that I have great faith in the opinion of this distinguished fish- 

 culturist. But before introducing this fish, the question should be 

 thoroughly considered, whether it would be expedient to increase the 

 number of voracious fish. The black bass likes to spawn on a bed of 

 large stones. I have seen some very large specimens of this fish which 

 are considered the oldest now in Germany. 



Eels. — All the eels found in the waters of Continental Europe came 

 from the sea as young eels, forming what is called the " mounting" of the 

 eels. The attempt to convey these young eels to places where they will 

 break their journey, or to guide them to such places if they do not go 

 there of their own accord, to some extent resembles the method pursued 

 at Comacchio and Polesine, where from time immemorial the eels have 

 been guided into the basins destined for them. The most enthusiastic 

 advocate of the introduction of these young eels into German waters is 

 Mr. Haack, who once procured them from France, but now obtains them 

 direct from Pisa, Italy, where they are brought into the market in enor- 

 mous quantities. 



