228 THE MIGRATION THEORY. [CHAP. vi. 



migration of the herring to and from the Arctic Eegions was 

 gravely revived in an unexpected quarter, as if that romance of 

 fish-life was still believed by modern naturalists to be the chief 

 episode in the natural history of Clupea harenyus; indeed in 

 the present edition of the Encyclopaedia Britannica this migra- 

 tory theory is still sustained (see article " Ichthyology"). The 

 original migration story which was invented by Pennant, or 

 rather was constructed by him from the theories of fishermen 

 old as it is, is worthy of being briefly recapitulated, as 

 affording a good point of view for a consideration of the 

 natural and economic history of the herring as now ascer- 

 tained : it was to the effect that in the inaccessible seas of the 

 high northern latitudes herrings were found in overwhelming 

 abundance, securing within the icy Arctic Circle a bounteous 

 feeding-ground, and at the same time a quiet and safe 

 retreat from, their numerous enemies. At the proper season, 

 inspired by some commanding impulse, vast bodies of this 

 fish gathered themselves together into one great army, and in 

 numbers far exceeding the power of imagination to picture 

 departed for the waters of Europe and America. The parti- 

 cular division of this great lieer, which was destined annually 

 to repopulate the British seas, and afford a plenteous food- 

 store for the people, was said to arrive at Iceland about 

 March, and to be of such amazing extent as to occupy a 

 surface more than equal to the dimensions of Great Britain 

 and Ireland, but subdivided, by a happy instinct, into 

 battalions five or six miles in length and three or four in 

 breadth, each line or column being led, according to the ideas 

 of fishermen, by herrings (probably the Alice and Tu-aite 

 shad) of more than ordinary size and sagacity. These 

 heaven-directed strangers were next supposed to strike on the 

 Shetland Islands, where they divided of themselves, as we are 

 told ; one division taking along the west side of Britain, whilst 

 the other took the east side, the result being an adequate and 



