THE NORTH SEA 91 



The milt, and roe show the condition under which 

 the capture takes place. When the object is 

 accomplished, the assembly dissolves, or disappears 

 as mysteriously as it grew. 



For a long time these creatures were the mystery 

 of the deep. Whence came they, and whither did 

 they go ? No doubt the migration of fishes is still 

 less understood than that of birds, and a good deal 

 of light remains to be thrown upon it. But there 

 seems reason to believe that herring do not dis- 

 appear as a body ; but simply scatter, and pass the 

 remainder of the year singly or in small shoals. 

 The eggs of the herring are demersal, or sunken ; 

 and there are certain places favourable for their 

 reception, whither they are led, as by an overmaster- 

 ing impulse, at the same time. Hence the shoals, 

 which as quickly vanish. 



It was long a puzzle how a creature so closely 

 allied to the herring as the sprat should have 

 floating eggs like the cod, and not sunken eggs 

 like the herring ; and, for a while, refuge was taken 

 in denial that the eggs in question really belonged 

 to the sprat. The easiest way out of such diffi- 

 culties is to confess our ignorance, and inability to 

 explain everything. 



Indignation has been freely expressed over the 



