128 THE BOTTOM OF TUE SEA. 



attacks of their numerous enemies.* However that 

 may be, some naturalists thiuk — and, as it appears to 

 us, with good reason — that duriiig the spawning 

 season the herring simply quits the level bottom of 

 the Ocean to deposit its eggs in the waters which 

 afford the protection of rocks or of abrupt eminences 

 against the force of the marine currents. 



Herrings do not obey simply the rule of caprice 

 in making their migrations. They appear to select 

 the coasts towards which they are travelling. As 

 all the paths of the sea may not be convenient for 

 tlie passage of a great host, though small detach- 

 ments may make their w^ay without difficulty, the 

 armies of herrings do not follow indifferently any 

 route. They traverse the regions where the staple 

 of their nourishment most abounds. Having visited 

 a coast they will return there freely the following 

 year. But suddenly, without any apparent reason, 

 they may disappear for a time, or perhaps for ever. 

 The arrival of the mackere] is sometimes the cause 

 of their departure. Being of larger size than the 

 herring, as well as better armed, the latter flies as at 

 sight of an enemy too formidable to be encountered. 



* The best authorities no longer countenance this tlieory. The 

 following paragraplis, in which the fact of the migration of herrings 

 is implic (1, are also open to dispute. The reader is referred to the 

 Kpccial works of Bertram and Mitchell. — Tb. 



