THE MIGRATION THEORY EXAMINED. 115 



the British coasts early in the year that is, in January 

 and February; and individuals are always to be found 

 in our seas. It was formerly asserted that they passed 

 the winter in the Icy Ocean, burying their heads deep in 

 tnud and sea-weed ; that towards the spring they mi- 

 grated southward, skirting the coasts of Ireland and 

 Scotland ; that then they poured into the Atlantic Ocean, 

 and divided into two columns, one of which sailed away 

 for the Mediterranean, while the other made for the 

 English Channel. All this is now exploded. It seems 

 to be true of the mackerel, as of the herring, that it re- 

 tires usually into the depths of the sea, but rises to the 

 surface and moves towards the coast as its spawning- 

 season approaches, which occurs earlier or later in the 

 year according to locality. 



On this point we may quote Mr. Yarrell : 

 It does not appear, as he remarks, to have been 

 sufficiently considered by the advocates of the migration 

 theory, that, inhabiting a medium which does not greatly 

 vary either in its temperature or productions, locally, 

 fishes are removed beyond the influence of the two princi- 

 pal causes which make a temporary change of situation 

 necessary. Independently of the difficulty of tracing the 

 course pursued through so vast an expanse of water, the 

 order of the appearance of the fish at different places on 

 the shores of the temperate and southern countries of 

 Europe is the reverse of what would have happened had 

 the aforesaid theory of migrations been true. " It is a 

 fact beyond dispute that the mackerel is caught, though 

 not plentifully, on some parts of our own coast in every 

 month of the year. We may conclude that it inhabits 

 all or nearly all the European seas ; and the law of 



