98 NATURAL HISTORY. 



In other cases, it is difficult to avoid the conclusion that 

 Pennant must have been endowed with a very lively imag- 

 ination; as, for example, in the circumstantial account 

 which he gives of the 'migrations' of the herring, part 

 of which may be quoted here. According to all our 

 modern knowledge, the herring is a local fish inhabit- 

 ing the German Ocean, the North Atlantic generally, 

 and the seas north of Asia. The shoals move from 

 place to place, but they are always present in larger 

 or smaller numbers in the seas which they inhabit, and 

 their movements are irregular, and apparently chiefly 

 governed by the conditions affecting food-supply. On 

 the other hand, Pennant, whose account has been referred 

 to by almost all writers on the subject, and was until 

 recently implicitly believed, gives a detailed account of 

 a set annual migration of the herrings to and from the 

 Arctic seas. ' The great winter rendezvous of the herring,' 

 he writes, ' is within the Arctic circle : there they continue 

 for many months in order to recruit themselves after the 

 fatigue of spawning, the seas within that space swarming 

 with insect food to a degree far greater than in our warmer 

 latitudes. 



' This mighty army begins to put itself into motion in 

 the spring ; we distinguish this vast body by that name, 

 for the word herring is derived from the German Heer, 

 an army, to express their numbers. 



' They begin to appear off the Shetland Isles in April 

 and May ; these are only forerunners of the grand shoal 

 which comes in June, and their appearance is marked by 

 certain signs, by the number of birds, such as gannets 

 and others, which follow to prey on them : but when the 



