CULTIVATED RIVERS. 75 



cept the fish in their free passage up and clown, until 

 they arrive at the falls of the Rhine at Schaffhausen, 

 a distance of nearly four hundred miles in length of 

 the main river, with various tributaries. The natural 

 instinct of the fish leads it to the uppermost moun- 

 tain streams, about sixty miles in length, lying be- 

 tween Basle and Schaffhausen ; the first, 300 miles 

 from the sea, is a large navigable muddy river, with 

 deep pools, and so wide that it is impossible to de- 

 stroy and exterminate the fish by any system of nets 

 or means of capture that has yet been invented, and, 

 moreover, it passes through the dominions of various 

 governments. I do not suppose that for 300 miles 

 any fish could be caught by lines and baits, and 

 comparatively but very few are caught by nets, ex- 

 cept near Rotterdam. The upper portions, supplied 

 with the purest cool snow water from the Alps, are 

 inaccessible to salmon, being intercepted by the falls 

 of the Rhine. 



I have previously shown that the. value of a salmon 

 fishery consists in the extent of the breeding ground, 

 and in the protection of the parent fish in the breed- 

 ing season. In the case of the Rhine, the fish are 

 bred in a country 300 miles from the sea, and caught 

 in Holland, where the people only invent the most 

 destructive nets that have ever been conceived of 

 800 yards in length, and worked by steamboats all 

 the year round, and yet a large stock of parent fish 

 escape, I have no doubt, owing to the great width of 

 the water, and deep pools. 



If such a river belonged to one State, or to one 

 owner, it is not possible to conceive the extent to 

 which it might be improved by cultivation. 



As the fish resort to the upper streams and above 

 Basle for the sole purpose of breeding, and when 

 they are out of season and unfit for human food they 

 are killed there, as they are in Holland, without re- 



