212 THU POPULAR SCIENCE MONTHLY. 



dustries must initiate for themselves and develop by their own re- 

 sources, and direct by the light of the consciousness of their distinctive 

 needs. Then, and not till then, shall we able to form an exact estimate 

 of the social and industrial conditions under which the apprenticeship 

 of the future may become a living reality. Then, and not till then, 

 will the apprenticeship of the futui'e constitute a powerful instrument, 

 not merely for the intellectual, moral, and social improvement of the 

 working-classes, but for the promotion of the wealth and prosperity 

 of the whole nation. 



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THE MIGKATIONS OF FISHES. 



By De. FKIEDEICH HEINCKE. 



THE periodical migrations of birds, grand as is the scale on which 

 they are performed, and fitted as they are to excite astonishment, 

 are insignificant compared with those which are made by the fishes of 

 the sea, A faint illustration of the stupendous character of these 

 movements is given off the west coast of Norway at the opening of the 

 fishing-season in the spring, when one, looking out over the sea in 

 quiet weather, will be witness of a stirring spectacle. The surface of 

 the water as far as the eye can reach glistens in diversified colors ; the 

 fiords and bays are alive wdth silvery streaks playing in constant move- 

 ment. The agitation is caused by the schools of herring, which are so 

 closely packed that a boat can not pass through them, an oar may be 

 made to stand up among them, and they may be dipped up in buckets 

 or caught with the hand by the thousand. The enemies of the her- 

 ring also come with them the mackerel, the sharks, and the dolphins 

 enlivening the scene with their graceful movements, with great flocks 

 of gulls. The sprat also appear in great multitudes on the coasts of 

 the North Sea, and the pilchards on the coasts of France and Spain 

 and the southwestern coasts of Great Britain in such immense schools 

 that millions of them have been taken w^ith a single draught of a large 

 net. 



The fish of the family of the Gadidm regularly visit the northern 

 seas in innumerable hosts. The codfish come between January and 

 March to the shallow bays of the Loffoden Islands and the banks of 

 ^N'ewfoundland, where their fishery gives employment to more than ten 

 thousand vessels and about one hundred and fifty thousand fishermen. 



Codfish and herring belong entirely to the sea. Many other fish 

 wander from the sea into the rivers. The sturgeon and the white-fish 

 go from the Caspian Sea to the Volga to spawn in such numbers that, 

 before the fishery became so destructive to them as it is, the cliildren 

 on the shore could scoop them up with their hands. Still more remark- 



