BONY FISHES 287 



evidence by the possession of a slender elongated body (compare with 

 pike) and a large caudal fin. However, these small crustaceans do not 

 always occur in such large quantities as to turn the sea-water into an 

 alimentary broth, and for this reason alone the capacity of rapid 

 swimming would be indispensable to the herring. (Compare with other 

 creatures which live on animals of small size, e.g., the swallow and most 

 of the song-birds.) 



E. Reproduction. 

 The eggs of the herring, being heavier than the water, sink to the 

 bottom. If they were deposited in the open ocean or in deep water, they 

 would sink into the fine mud which everywhere forms the bottom of the 

 deep sea. Here, however, there is a dearth of warmth and of oxygen 

 (respiration), both of which are present in abundance in the shallow 

 waters along the coast, where, under the influence of sunlight, an 

 abundant plant life is developed (seaweeds, sea - grass, etc. ; plants 

 separate oxygen under the influence of sunlight). It is to such places 

 that the herring must betake itself to prevent its species from perishing. 

 The fish for the purpose of spawning associate in enormous numbers, 

 forming gigantic hosts or shoals, which swim towards the coast. The 

 expert fisherman is able to recognise a shoal of herrings even from a 

 distance by the bright reflection in the sky, which is caused by the 

 reflection of the rays of the sun or moon from the silvery coat of the fish. 

 As they swim above their spawning grounds, the fish discharge their eggs, 

 which sink to the bottom, and owing to their albuminous envelope 

 adhere to plants and stones. Having deposited the spawn, the fish 

 which have escaped capture once more turn their course eastwards. The 

 different varieties of herrings (see Section B) spawn at different seasons. 



F. Herring Fishery. 



It is the migratory shoals which approach the land in order to spawn 

 which are most eagerly awaited by the fishermen. For the purpose of 

 ensnaring the fish gigantic nets are let down vertically into the sea and 

 tied together by their ends so as to form immense walls of meshwork. 

 The meshes of these nets are exactly of a width to allow the head of a 

 full-grown herring to pass through them, but to cause it to be held fast 

 by the gill-covers if it tries to escape backwards. When the nets are full 

 they are lifted out of the water, the herrings are shaken out and conveyed 

 to the coast, where they are prepared (see Section A) for transport. 



An enormous number of herrings (estimated at 10,000 millions) are 

 thus caught every year. (The value of the herrings imported into 

 Germany alone from other countries amounts to ^2,000,000.) And 

 these numbers, according to the calculations of experts, amount to not 



