20 



stream; and, at all events, M. Costers plan is more 

 curious than practically useful. 



XI. 



And now to conclude. It would be idle to dwell on 

 the immense importance of stocking our waters with 

 millions of fish, that will be apparent to every one ; and 

 we shall be much disappointed if the system described be 

 not taken up as warmly, and practised as extensively, in 

 this country as it has been in France. 



But in addition to its commercial importance as a new 

 branch of industry, and its social value as affording a 

 vast addition to the people's food, this system possesses 

 the advantage of opening a boundless field to scientific 

 curiosity. In the Danube and the Rhine, the Elbe and 

 the Spree, and almost every other river in Germany ; in 

 the rivers and lakes of Eussia and northern Europe ; in 

 the lakes of Switzerland ; in the rivers of France ; there 

 exist either species of fish which we do not possess, or 

 peculiar varieties of species which we do possess; and 

 there is every reason to believe that very many of them, 

 if not all, might be naturalized in our waters. The 

 same remark will apply to some of the fish in the rivers 

 and lakes of America, and even of the rivers of Asia or 

 Africa. Nor is this all. Why should not the different 

 races of fish be crossed, as well as those of animals and 

 plants ? Who can tell what the ingenuity of man may 

 not produce by the happy adaptation of the milt of one 

 description of male to the eggs of another description of 

 female ? 



