19 



feed on. Thus, when the system of artificial production 

 is employed on an extensive scale, it will be necessary to 

 breed some of the smaller descriptions of fish as food for 

 the larger. In reservoirs, however, different sorts of 

 food may be offered by way of experiment. 



X. 



Although it has been stated that it is necessary to 

 place the fecundated eggs in the bed of a stream, it may 

 be mentioned that an eminent French naturalist, M. 

 Coste, professor at the College de France at Paris, has 

 discovered that the stream may be done without ; he has 

 produced salmon in a tub. 



He caused a large tub to be constructed, with con- 

 duits or canals placed one beneath the other, in such a 

 way that water, on entering by the upper part of one 

 canal, flowed to the lower part, and then descended into 

 the canal beneath ; and after flowing along it, descended 

 into the one below, and so on until at last it escaped 

 from the vessel. In each canal he placed a layer of 

 gravel and pebbles, and on these a quantity of salmon's 

 eggs, fecundated by Remy and Gehin's system, and 

 sent up from the reservoirs of Huninguen, a distance of 

 several hundred miles. The water flowed from a cistern, 

 through an ordinary cock; and the only precaution 

 taken was to keep the stream constantly going. 



In due time the exclusion or hatching of the eggs 

 took place, and the salmon are now alive and well. 



By M. Coste's system several different descriptions of 

 fish can be produced at the same time. But it may, 

 perhaps, be doubted whether the fish will possess the 

 same vigour or qualities as if produced in a natural 



